@booklet {Dagnino, title = {{Comparison of Objective Functionals in Seismic Full Waveform Inversion}}, year = {Submitted}, publisher = {European Association of Geoscientists and Engineers}, abstract = {The FWI method is a powerful tool that allows one to obtain high-resolution information from the subsurface. However, the method is highly non-linear as in the convergence to the solution it might get trapped in local-minima. Among other techniques, it becomes crucial a suitable choice of the objective function. We have selected five objective functions to perform a comparative study under a common 2D-acoustic FWI scheme: the L2-nom, cross-correlation travel time (CCTT), non-integration-method (NIM), envelope and phase objective functions. We test with a 2D-canonical model the susceptibility of the functions to the initial model perturbations. To complete de study with a more realistic synthetic example we test the functions with the Marmousi model. The L2-norm and phase objective functions give the highest resolution images and the CCTT, NIM and envelope objective functions lead to smooth models. However in realistic initial conditions, L2 and phase misfits fail in recovering the velocity model in contrast to the CCTT, NIM and envelope functions that maintain a more consistent behavior}, author = {Dagnino, D and Jiminez-Tejero, C E and Ranero, C{\'e}sar R and Sallares, Valenti} } @article {Cameselle, title = {{Large-scale margin collapse during Messinian early sea-level drawdown: The SW Valencia Trough, NW Mediterranean}}, journal = {Basin Research}, year = {Submitted}, keywords = {for review purposes only}, doi = {10.1111/bre.12170}, author = {Cameselle, Alejandra L and Urgeles, R} } @article {N{\'u}{\~n}ez-Corn{\'u}201659, title = {{Geophysical studies across rivera plate and jalisco block, Mexico: Tsujal project}}, journal = {Seismological Research Letters}, volume = {87}, number = {1}, year = {2016}, pages = {59{\textendash}72}, abstract = {In the spring of 2014, an onshore-offshore geophysical experiment ("Crustal Characterization of the Rivera plate-Jalisco Block Boundary and Its Implications for Seismic and Tsunami Hazard Assessment") was carried out in the frame of theTsuJal project to define the crustal architecture of the western Mexican active margin and identify potential structural sources that can trigger earthquakes and tsunamis at the convergence between the Rivera plate (RP) and the Jalisco Block (JB) within the North American plate. In this work, we present the preliminary results about bathymetric, structural geology, and wide-angle seismic data of the southern coast of Bah{\'\i}a de Banderas. These data indicate the slab thickness in this area is about 10 km and presents a dip angle of about 8. Continental crustal thickness below Puerto Vallarta is about 20 km, but no evidences of continental Moho and clear subduction features (trench, accretionary prism) are observed. Nevertheless, this model supports the hypothesis that the region of Bah{\'\i}a de Banderas is under strong crustal stresses generating structural lineaments with the same trends offshore and inland due to the convergence of the RP against the JB. Most of the seismicity reported can be associated with the main structural lineaments. Moreover, the Banderas Canyon (BC) is apparently in an eastward opening process, which seems to continue through the Rio Pitillal river valley; no seismic or morphological evidences were found to suggest the BC is a continuation of the Vallarta graben. Offshore, the Sierra de Cleofas, located south of Mar{\'\i}a Cleofas Island, marks the limit between the RP and the JB along 100 km. It may be the result of the RP pushing against the JB establishing the beginning of the current subduction process, with associated seismic activity. If a subduction type earthquake occurs in this area, the associated magnitude will be about 7.5 and could have a tsunamigenic effect.}, doi = {10.1785/0220150144}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84954306785\&partnerID=40\&md5=ad4bbdb5d2b001b4510745d3e92ea302}, author = {N{\'u}{\~n}ez-Corn{\'u}, F J and C{\'o}rdoba, D and Da{\~n}obeitia, J J and Bandy, W L and Figueroa, M O and Bartolom{\'e}, R and N{\'u}{\~n}ez, D and Zamora-Camacho, A and Esp{\'\i}ndola, J M and Castell{\'o}n, A and Escudero, C R and Trejo-G{\'o}mez, E and De Jes{\'u}s Escalona-Alc{\'a}zar, F and Plascencia, C S and Alejandro Nava, F and Mortera, C} } @article {Biescas2016, title = {{Synthetic Modeling for an Acoustic Exploration System for Physical Oceanography}}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {33}, number = {1}, year = {2016}, pages = {191{\textendash}200}, publisher = {American Meteorological Society}, abstract = {AbstractMarine multichannel seismic (MCS) data, used to obtain structural reflection images of the earth?s subsurface, can also be used in physical oceanography exploration. This method provides vertical and lateral resolutions of O(10?100) m, covering the existing observational gap in oceanic exploration. All MCS data used so far in physical oceanography studies have been acquired using conventional seismic instrumentation originally designed for geological exploration. This work presents the proof of concept of an alternative MCS system that is better adapted to physical oceanography and has two goals: 1) to have an environmentally low-impact acoustic source to minimize any potential disturbance to marine life and 2) to be light and portable, thus being installed on midsize oceanographic vessels. The synthetic experiments simulate the main variables of the source, shooting, and streamer involved in the MCS technique. The proposed system utilizes a 5-s-long exponential chirp source of 208 dB relative to 1 ?Pa at 1 m with a frequency content of 20?100 Hz and a relatively short 500-m-long streamer with 100 channels. This study exemplifies through numerical simulations that the 5-s-long chirp source can reduce the peak of the pressure signal by 26 dB with respect to equivalent air gun?based sources by spreading the energy in time, greatly reducing the impact to marine life. Additionally, the proposed system could be transported and installed in midsize oceanographic vessels, opening new horizons in acoustic oceanography research.}, issn = {0739-0572}, doi = {10.1175/JTECH-D-15-0137.1}, url = {http://dx.doi.org/10.1175/JTECH-D-15-0137.1}, author = {Biescas, Berta and Ruddick, Barry and Kormann, Jean and Sallares, Valenti and Nedimovi{\'c}, Mladen R and Carniel, Sandro} } @article {Jim{\'e}nezTejero2015632, title = {{Comparative study of objective functions to overcome noise and bandwidth limitations in full waveform inversion}}, journal = {Geophysical Journal International}, volume = {203}, number = {1}, year = {2015}, pages = {632{\textendash}645}, abstract = {Ongoing works on full waveform inversion (FWI) are yielding an increasing number of objective functions as alternative to the traditional L2-waveform. These studies aim at designing more robust functions and inversion strategies to reduce the intrinsic dependence of the FWI results on (1) the initial model and (2) the lowest frequency present in field data. In this work, we perform a comparative study of five objective functions in time domain under a common 2-D-acoustic FWI scheme using the Marmousi model as benchmark. In particular, we compare results obtained with L2-based functions that consider the minimization of different wave attributes; the waveform-based, non-integration-method; instantaneous envelope; a modified version of the wrapped instantaneous phase and an improved version of the cross-correlation travel time (CCTT) method; and hybrid strategies combining some of them. We evaluate the robustness of these functionals as a function of their performance with and without low frequencies in the data and the presence of random white Gaussian noise. Our results reveal promising strategies to invert noisy data with limited low-frequency content (>=4 Hz), which is the single strategy using the instantaneous phase objective function followed by the hybrid strategies using the instantaneous phase or CCTT as initial models, in particular the combinations [I. Phase + Waveform], [CCTT + Waveform] and [CCTT + I. Phase]. {\textcopyright} The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, doi = {10.1093/gji/ggv288}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84942124341\&partnerID=40\&md5=a3d1892b9dda25cdcea5fea23bef2d14}, author = {Jim{\'e}nez Tejero, C.E.a and Dagnino, D.a and Sallar{\`e}s, V.a and Ranero, C.R.b} } @article {Prada201563, title = {{The complex 3-D transition from continental crust to backarc magmatism and exhumed mantle in the Central Tyrrhenian basin}}, journal = {Geophysical Journal International}, volume = {203}, number = {1}, year = {2015}, pages = {63{\textendash}78}, abstract = {Geophysical data from the MEDOC experiment across the Northern Tyrrhenian backarc basin has mapped a failed rift during backarc extension of cratonic Variscan lithosphere. In contrast, data across the Central Tyrrhenian have revealed the presence of magmatic accretion followed by mantle exhumation after continental breakup. Here we analyse the MEDOC transect E-F, which extends from Sardinia to the Campania margin at 40.5{\textdegree}N, to define the distribution of geological domains in the transition from the complex Central Tyrrhenian to the extended continental crust of the Northern Tyrrhenian. The crust and uppermost mantle structure along this \~{}400-km-long transect have been investigated based on wide-angle seismic data, gravity modelling and multichannel seismic reflection imaging. The P-wave tomographic model together with a P-wave-velocity-derived density model and the multichannel seismic images reveal seven different domains along this transect, in contrast to the simpler structure to the south and north. The stretched continental crust under Sardinia margin abuts the magmatic crust of Cornaglia Terrace, where accretion likely occurred during backarc extension. Eastwards, around Secchi seamount, a second segment of thinned continental crust (7-8 km) is observed. Two short segments of magmatically modified continental crust are separated by the \~{}5-km-wide segment of the Vavilov basin possibly made of exhumed mantle rocks. The eastern segment of the 40.5{\textdegree}N transect E-F is characterized by continental crust extending from mainland Italy towards the Campania margin. Ground truthing and prior geophysical information obtained north and south of transect E-F was integrated in this study to map the spatial distribution of basement domains in the Central Tyrrhenian basin. The northward transition of crustal domains depicts a complex 3-D structure represented by abrupt spatial changes of magmatic and non-magmatic crustal domains. These observations imply rapid variations of magmatic activity difficult to reconcile with current models of extension of continental lithosphere essentially 2-D over long distances. {\textcopyright} The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, doi = {10.1093/gji/ggv271}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84942122080\&partnerID=40\&md5=02bdb76af30a3b605991623f90757147}, author = {Prada, M.a and Sallar{\`e}s, V.a and Ranero, C.R.b and Vendrell, M.G.a and Grevemeyer, I.c and Zitellini, N.d and de Franco, R.e} } @article {Giaconia2015, title = {{Compressional tectonic inversion of the Algero-Balearic basin: Latemost Miocene to present oblique convergence at the Palomares margin (Western Mediterranean)}}, journal = {Tectonics}, volume = {34}, number = {7}, year = {2015}, month = {jul}, pages = {1516{\textendash}1543}, keywords = {10.1002/2015TC003861 and Active tectonics, Abubacer anticline, multichannel seismics, Palomares fault zone, Tectonic inversion, Western Mediterranean}, issn = {02787407}, doi = {10.1002/2015TC003861}, url = {http://doi.wiley.com/10.1002/2015TC003861}, author = {Giaconia, Flavio and Booth-Rea, Guillermo and Ranero, C{\'e}sar R and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Calahorrano, Alcinoe and Lo Iacono, Claudio and Vendrell, Montserrat G and Cameselle, Alejandra L and Costa, Sergio and G{\'o}mez de la Pe{\~n}a, Laura and Mart{\'\i}nez-Loriente, Sara and Perea, Hector and Vi{\~n}as, Marina} } @article {Cameselle2015, title = {{The continent-ocean transition on the northwestern South China Sea}}, journal = {Basin Research}, year = {2015}, pages = {n/a{\textendash}{\textendash}n/a}, issn = {0950091X}, doi = {10.1111/bre.12137}, url = {http://doi.wiley.com/10.1111/bre.12137}, author = {Cameselle, Alejandra L and Ranero, C{\'e}sar R and Franke, Dieter and Barckhausen, Udo} } @article {Bangs201567, title = {{Fluid accumulation along the Costa Rica subduction thrust and development of the seismogenic zone}}, journal = {Journal of Geophysical Research B: Solid Earth}, volume = {120}, number = {1}, year = {2015}, pages = {67{\textendash}86}, abstract = {In 2011 we acquired an 11 {\texttimes} 55 km, 3-D seismic reflection volume across the Costa Rica margin, NW of the Osa Peninsula, to accurately image the subduction thrust in 3-D, to examine fault zone properties, and to infer the hydrogeology that controls fluid accumulation along the thrust. Following processing to remove water column multiples, noise, and acquisition artifacts, we constructed a 3-D seismic velocity model for Kirchhoff prestack depth migration imaging. Images of the plate boundary thrust show high-reflection amplitudes underneath the middle to lower slope that we attribute to fluid-rich, poorly drained portions of the subduction thrust. At \~{} 5 km subseafloor, beneath the upper slope, the plate interface abruptly becomes weakly reflective, which we interpret as a transition to a well-drained subduction thrust. Mineral dehydration during diagenesis may also diminish at 5 km subseafloor to reduce fluid production and contribute to the downdip change from high to low amplitude. There is also a layered fabric and systems of both thrust and normal faults within the overriding plate that form a "plumbing system." Faults commonly have fault plane reflections and are presumably fluid charged. The faults and layered fabric form three compartmentalized hydrogeologic zones: (1) a shallow NE dipping zone beneath the slope, (2) a steeply SW dipping zone beneath the shelf slope break, and (3) a NE dipping zone beneath the shelf. The more direct pathway in the middle zone drains the subduction thrust more efficiently and contributes to reduced fluid pressure, elevates effective stress, and creates greater potential for unstable coseismic slip. {\textcopyright}2014. American Geophysical Union. All Rights Reserved.}, doi = {10.1002/2014JB011265}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84924020398\&partnerID=40\&md5=d49719196f3f40ccbd90cc13a525e689}, author = {Bangs, N.L.a and McIntosh, K.D.a and Silver, E.A.b and Kluesner, J.W.b and Ranero, C.R.c} } @article {Moreno201578, title = {{Quaternary tectonic activity of the Carboneras Fault in the La Serrata range (SE Iberia): Geomorphological and chronological constraints}}, journal = {Tectonophysics}, volume = {663}, year = {2015}, pages = {78{\textendash}94}, abstract = {The Eastern Betic Shear Zone (EBSZ) in Southern Iberia is known to accommodate part of the 4-5mm/yr convergence between Africa and Iberia, but its seismic hazard is not sufficiently understood for an accurate risk assessment. One of the main structures of the EBSZ, the left-lateral 150km-long Carboneras Fault, displays no clear instrumental and historical activity despite being morphologically expressive. Detailed geomorphological mapping, geochronological analysis, and structural observation on the La Serrata segment of the Carboneras Fault were designed to investigate its recent evolution. Quaternary sediments and geomorphic features were targeted and 42 new numerical ages were obtained based on 66 samples (thermoluminescence, U-series, 14C, 10Be). The chronological framework of La Serrata was constructed by combining these numerical ages with a conceptual model previously developed in the region, which assumes that alluvial fan aggradation was produced during cold and dry periods (glacials and stadials), whereas stability and phases of calcrete formation were favored during warm and wetter periods (interglacials and interstadials). The spatial distribution of dated alluvial fans suggests an early phase of uplift that probably occurred between 1Ma and 56.6ka in the northeastern portion of the study area, whereas in the southwest sector the main uplift phase occurred later than 110.3ka. A decline in fault activity would have taken place after 30.8ka. Vertically offset dated units indicate minimum dip-slip rates of 0.05mm/yr and 0.18mm/yr, averaged for the last 1Ma and the last 110.3ka, respectively. Deflected channels and associated dated units yield a minimum left-lateral strike-slip rate of 1.31mm/yr, averaged for the last 110.3ka. The most recent fault movement of the fault could be younger than AD 637. Our results suggest therefore that the Carboneras Fault is among the fastest in Iberia, and should be considered in future hazard analyses. {\textcopyright} 2015 Elsevier B.V.}, doi = {10.1016/j.tecto.2015.08.016}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84955683900\&partnerID=40\&md5=e4a4acb51d89920f2e6fbd0c738b7730}, author = {Moreno, X.a b and Masana, E.a and Pall{\`a}s, R.a and Gr{\`a}cia, E.b and Rod{\'e}s, {\'A}.a c and Bordonau, J.a} } @mastersthesis {Cameselle2015, title = {{Sedimentary processes and resulting continental margin configuration during large-scale sea-level drawdown: The Messinian Salinity Crisis in the Western Mediterranean Sea}}, year = {2015}, pages = {233}, school = {Universitat de Barcelona}, type = {phdThesis}, author = {Cameselle, Alejandra L} } @article {Grevemeyer2015, title = {{Seismicity and active tectonics in the Alboran Sea, Western Mediterranean: Constraints from an offshore-onshore seismological network and swath bathymetry data}}, journal = {Journal of Geophysical Research B: Solid Earth}, year = {2015}, abstract = {Seismicity and tectonic structure of the Alboran Sea were derived from a large amphibious seismological network deployed in the offshore basins and onshore in Spain and Morocco, an area where the convergence between the African and Eurasian plates causes distributed deformation. Crustal structure derived from local earthquake data suggests that the Alboran Sea is underlain by thinned continental crust with a mean thickness of about 20km. During the 5months of offshore network operation, a total of 229 local earthquakes were located within the Alboran Sea and neighboring areas. Earthquakes were generally crustal events, and in the offshore domain, most of them occurred at crustal levels of 2 to 15km depth. Earthquakes in the Alboran Sea are poorly related to large-scale tectonic features and form a 20 to 40km wide NNE-SSW trending belt of seismicity between Adra (Spain) and Al Hoceima (Morocco), supporting the case for a major left-lateral shear zone across the Alboran Sea. Such a shear zone is in accord with high-resolution bathymetric data and seismic reflection imaging, indicating a number of small active fault zones, some of which offset the seafloor, rather than supporting a well-defined discrete plate boundary fault. Moreover, a number of large faults known to be active as evidenced from bathymetry, seismic reflection, and paleoseismic data such as the Yusuf and Carboneras faults were seismically inactive. Earthquakes below the Western Alboran Basin occurred at 70 to 110km depth and hence reflected intermediate depth seismicity related to subducted lithosphere. {\textcopyright} 2015. American Geophysical Union. All Rights Reserved.}, doi = {10.1002/2015JB012073}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84949685458\&partnerID=40\&md5=f8fcd419da7cfea696b0fd9d4be46078}, author = {Grevemeyer, I.a and Gr{\`a}cia, E.b and Villase{\~n}or, A.c and Leuchters, W.a and Watts, A.B.d} } @article {Hensen01042015, title = {{Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea}}, journal = {Geology}, volume = {43}, number = {4}, year = {2015}, pages = {339{\textendash}342}, abstract = {We report on newly discovered mud volcanoes located at \~{}4500 m water depth \~{}90 km west of the deformation front of the accretionary wedge of the Gulf of Cadiz, and thus outside of their typical geotectonic environment. Seismic data suggest that fluid flow is mediated by a >400-km-long strike-slip fault marking the transcurrent plate boundary between Africa and Eurasia. Geochemical data (Cl, B, Sr, 87Sr/86Sr, $δ$18O, $δ$D) reveal that fluids originate in oceanic crust older than 140 Ma. On their rise to the surface, these fluids receive strong geochemical signals from recrystallization of Upper Jurassic carbonates and clay-mineral dehydration in younger terrigeneous units. At present, reports of mud volcanoes in similar deep-sea settings are rare, but given that the large area of transform-type plate boundaries has been barely investigated, such pathways of fluid discharge may provide an important, yet unappreciated link between the deeply buried oceanic crust and the deep ocean.}, doi = {10.1130/G36359.1}, url = {http://geology.gsapubs.org/content/43/4/339.abstract}, author = {Hensen, Christian and Scholz, Florian and Nuzzo, Marianne and Valadares, Vasco and Gr{\'a}cia, Eul{\`a}lia and Terrinha, Pedro and Liebetrau, Volker and Kaul, Norbert and Silva, Sonia and Mart{\'\i}nez-Loriente, Sara and Bartolom{\'e}, Rafael and Pi{\~n}ero, Elena and Magalh{\~a}es, Vitor H and Schmidt, Mark and Weise, Stephan M and Cunha, Marina and Hilario, Ana and Perea, Hector and Rovelli, Lorenzo and Lackschewitz, Klas} } @article {Garcia20154261, title = {{Structure of the mantle beneath the Alboran Basin from magnetotelluric soundings}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {16}, number = {12}, year = {2015}, pages = {4261{\textendash}4274}, abstract = {We present results of marine MT acquisition in the Alboran sea that also incorporates previously acquired land MT from southern Spain into our analysis. The marine data show complex MT response functions with strong distortion due to seafloor topography and the coastline, but inclusion of high resolution topography and bathymetry and a seismically defined sediment unit into a 3-D inversion model has allowed us to image the structure in the underlying mantle. The resulting resistivity model is broadly consistent with a geodynamic scenario that includes subduction of an eastward trending plate beneath Gibraltar, which plunges nearly vertically beneath the Alboran. Our model contains three primary features of interest: a resistive body beneath the central Alboran, which extends to a depth of \~{}150 km. At this depth, the mantle resistivity decreases to values of \~{}100 Ohm-m, slightly higher than those seen in typical asthenosphere at the same depth. This transition suggests a change in slab properties with depth, perhaps reflecting a change in the nature of the seafloor subducted in the past. Two conductive features in our model suggest the presence of fluids released by the subducting slab or a small amount of partial melt in the upper mantle (or both). Of these, the one in the center of the Alboran basin, in the uppermost-mantle (20-30 km depth) beneath Neogene volcanics and west of the termination of the Nekkor Fault, is consistent with geochemical models, which infer highly thinned lithosphere and shallow melting in order to explain the petrology of seafloor volcanics. {\textcopyright} 2015. American Geophysical Union. All Rights Reserved.}, doi = {10.1002/2015GC006100}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84955347580\&partnerID=40\&md5=9ce7a52b6fe74ed86c20613d5230a4db}, author = {Garcia, X.a and Seill{\'e}, H.b and Elsenbeck, J.c and Evans, R.L.c and Jegen, M.d and H{\"o}lz, S.d and Ledo, J.e and Lovatini, A.f and Marti, A.e and Marcuello, A.e and Queralt, P.e and Ungarelli, C.f and Ranero, C.R.g} } @article {Geersen2015, title = {{Subducting seamounts control interplate coupling and seismic rupture in the 2014 Iquique earthquake area}}, journal = {Nature Communications}, volume = {6}, year = {2015}, abstract = {To date, the parameters that determine the rupture area of great subduction zone earthquakes remain contentious. On 1 April 2014, the Mw 8.1 Iquique earthquake ruptured a portion of the well-recognized northern Chile seismic gap but left large highly coupled areas un-ruptured. Marine seismic reflection and swath bathymetric data indicate that structural variations in the subducting Nazca Plate control regional-scale plate-coupling variations, and the limited extent of the 2014 earthquake. Several under-thrusting seamounts correlate to the southward and up-dip arrest of seismic rupture during the 2014 Iquique earthquake, thus supporting a causal link. By fracturing of the overriding plate, the subducting seamounts are likely further responsible for reduced plate-coupling in the shallow subduction zone and in a lowly coupled region around 20.5{\textdegree}S. Our data support that structural variations in the lower plate influence coupling and seismic rupture offshore Northern Chile, whereas the structure of the upper plate plays a minor role. {\textcopyright} 2015 Macmillan Publishers Limited. All rights reserved.}, doi = {10.1038/ncomms9267}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84942875520\&partnerID=40\&md5=c48e69118579945090a1454f6db7407e}, author = {Geersen, J.a and Ranero, C.R.b and Barckhausen, U.c and Reichert, C.c} } @article {Mel{\'e}ndez2015158, title = {{TOMO3D: 3-D joint refraction and reflection traveltime tomography parallel code for active-source seismic data-synthetic test}}, journal = {Geophysical Journal International}, volume = {203}, number = {1}, year = {2015}, pages = {158{\textendash}174}, abstract = {We present a new 3-D traveltime tomography code (TOMO3D) for the modelling of active-source seismic data that uses the arrival times of both refracted and reflected seismic phases to derive the velocity distribution and the geometry of reflecting boundaries in the subsurface. This code is based on its popular 2-D version TOMO2D from which it inherited the methods to solve the forward and inverse problems. The traveltime calculations are done using a hybrid ray-tracing technique combining the graph and bending methods. The LSQR algorithm is used to perform the iterative regularized inversion to improve the initial velocity and depth models. In order to cope with an increased computational demand due to the incorporation of the third dimension, the forward problem solver, which takes most of the run time (\~{}90 per cent in the test presented here), has been parallelized with a combination of multi-processing and message passing interface standards. This parallelization distributes the ray-tracing and traveltime calculations among available computational resources. The code{\textquoteright}s performance is illustrated with a realistic synthetic example, including a checkerboard anomaly and two reflectors, which simulates the geometry of a subduction zone. The code is designed to invert for a single reflector at a time. A data-driven layer-stripping strategy is proposed for cases involving multiple reflectors, and it is tested for the successive inversion of the two reflectors. Layers are bound by consecutive reflectors, and an initial velocity model for each inversion step incorporates the results from previous steps. This strategy poses simpler inversion problems at each step, allowing the recovery of strong velocity discontinuities that would otherwise be smoothened. {\textcopyright} The Authors 2015. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, doi = {10.1093/gji/ggv292}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84942105766\&partnerID=40\&md5=95ac8480fd67102b8f5322381f9ff8ef}, author = {Mel{\'e}ndez, A.a and Korenaga, J.b and Sallar{\`e}s, V.a and Miniussi, A.c and Ranero, C.R.d} } @inbook {Martinez-LorienteS.GraciaE;BartolomeR;SallaresV;Perea2014, title = {{Active faulting in the Mesozoic oceanic lithosphere offshore the SW Iberian margin. Significance for earthquake and tsunami hazard}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {81{\textendash}84}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {Martinez-Loriente, S. and Gr{\`a}cia, E and Bartolom{\'e}, R and SALLARES, V and Perea, H} } @booklet {Harders2014, title = {{Characterization of Submarine Landslide Complexes Offshore Costa Rica: An Evolutionary Model Related to Seamount Subduction}}, year = {2014}, month = {dec}, publisher = {Springer International Publishing}, abstract = {Offshore Costa Rica large seamounts under-thrust the continental convergent margin causing slides of complex morphology. The large dimension of the structures has attracted previous investigations and their basic characteristics are known. However, no detailed mapping of their complex morphology has been reported. Here we present a detailed mapping of the failure-related structures and deposits. We use deep-towed sidescan sonar data, aided by multibeam bathymetry to analyze their geometry, geomorphologic character, backscatter intensity, and spatial distribution. Those observations are used to analyze the relationship between landslide characteristics and abundance, to the changes in the style of deformation caused by the subduction of seamounts to progressively greater depth under the margin.}, isbn = {10.1007/978-3-319-00972-8\_34}, doi = {10.1007/978-3-319-00972-8\_34 .}, url = {http://oceanrep.geomar.de/22515/}, author = {Harders, Rieka and Weinrebe, Wilhelm and Ranero, Cesar R.} } @conference {Tejero2014, title = {{Comparison of objective functionals in seismic full waveform inversion}}, booktitle = {76th European Association of Geoscientists and Engineers Conference and Exhibition 2014: Experience the Energy - Incorporating SPE EUROPEC 2014}, year = {2014}, pages = {2819{\textendash}2823}, publisher = {EAGE Publishing BV}, organization = {EAGE Publishing BV}, abstract = {The FWI method is a powerful tool that allows one to obtain high-resolution information from the subsurface. However, the method is highly non-linear as in the convergence to the solution it might get trapped in local-minima. Among other techniques, it becomes crucial a suitable choice of the objective function. We have selected five objective functions to perform a comparative study under a common 2Dacoustic FWI scheme: the L2-nom, cross-correlation travel time (CCTT), non-integration-method (NIM), envelope and phase objective functions. We test with a 2D-canonical model the susceptibility of the functions to the initial model perturbations. To complete de study with a more realistic synthetic example we test the functions with the Marmousi model. The L2-norm and phase objective functions give the highest resolution images and the CCTT, NIM and envelope objective functions lead to smooth models. However in realistic initial conditions, L2 and phase misfits fail in recovering the velocity model in contrast to the CCTT, NIM and envelope functions that maintain a more consistent behavior.}, isbn = {9781632666949}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84907396478\&partnerID=tZOtx3y1}, author = {Tejero, C. E Jimenez and Dagnino, D. and Sallar{\`e}s, V. and Ranero, C.} } @article {Garcia2014a, title = {{Constraints on a shallow offshore gas environment determined by a multidisciplinary geophysical approach: The Malin Sea, NW Ireland}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {15}, number = {4}, year = {2014}, pages = {867{\textendash}885}, issn = {15252027}, doi = {10.1002/2013GC005108}, url = {http://doi.wiley.com/10.1002/2013GC005108}, author = {Garcia, Xavier and Monteys, Xavier and Evans, Rob L. and Szpak, Michal} } @article {Cameselle2014, title = {{The continent-ocean transition of the rifted South China continental margin}}, journal = {EGU General Assembly Conference Abstracts}, volume = {16}, year = {2014}, month = {may}, pages = {14917}, url = {http://adsabs.harvard.edu/abs/2014EGUGA..1614917C}, author = {Cameselle, Alejandra L. and Ranero, C{\'e} and sar R. and Franke, Dieter and Barckhausen, Udo} } @article {Moeller2014, title = {{Crustal thinning in the northern Tyrrhenian Rift: Insights from multichannel and wide-angle seismic data across the basin}}, volume = {119}, number = {3}, year = {2014}, pages = {1655{\textendash}1677}, url = {http://apps.isiknowledge.com/full\_record.do?product=UA\&search\_mode=GeneralSearch\&qid=5\&SID=S1AN85ZGXvSBJ7DKZfo\&page=1\&doc=3}, author = {Moeller, S. and Grevemeyer, I. and Ranero, C. R.} } @article {Hanebuth2014, title = {{Drilling Glacial Deposits in Offshore Polar Regions}}, journal = {Eos, Transactions American Geophysical Union}, volume = {95}, number = {31}, year = {2014}, month = {aug}, pages = {277{\textendash}278}, publisher = {Blackwell Publishing Ltd}, abstract = {High latitudes are of fundamental importance in the Earth{\textquoteright}s climate system - they house ice sheets that govern global sea level heights, influence how much solar energy is reflected back to space, and create deep and bottom waters that drive the ocean{\textquoteright}s ability to circulate energy and nutrients across the globe. {\textcopyright}2014. American Geophysical Union. All Rights Reserved.}, keywords = {Arctic region, Glacigenic drilling, grounding zone wedges}, issn = {00963941}, doi = {10.1002/2014EO310001}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905693212\&partnerID=tZOtx3y1}, author = {Hanebuth, Till J. J. and Rebesco, Michele and Urgeles, Roger and Lucchi, Renata G. and Freudenthal, Tim} } @inbook {PereaHGraciaE.BartolomeRGomezdelaPenaL.Martinez-LorienteS.MorenoX.DeMolB.TelloO.BallesterosM.2014, title = {{Evidences of quaternary active faults across the Djibouti high and the Adra Ridge (Alboran Sea)}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {97{\textendash}100}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {Perea, H and Gr{\`a}cia, E. and Bartolom{\'e}, R and G{\'o}mez de la Pe{\~n}a, L. and Martinez-Loriente, S. and Moreno, X. and De Mol, B. and Tello, O. and Ballesteros, M. and cruise Party, EVENT-DEEP} } @inbook {MasanaOrtunoM.E.FerraterM.PereaH.BaizeS.EcheverriaA.PallasR.GarciaMelendezE.Martinez-DiazJ.J.andRockwell2014, title = {{Fine grained bodies as evidence of {\textquotedblleft}dusty{\textquotedblright} paleoearthquakes in the Alhama de Murcia Fault geological record}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {23{\textendash}26}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {Masana, Ortu{\~n}o, M., E. and Ferrater, M. and Perea, H. and Baize, S. and Echeverria, A. and Pall{\`a}s, R. and Garc{\'\i}a Mel{\'e}ndez, E. and Mart{\'\i}nez-D{\'\i}az and J.J. and Rockwell, T.} } @booklet {Rebesco2014, title = {{Grounding zone wedges , Kveithola Trough ( NW Barents Sea )}}, journal = {Atlas of Submarine Glacial Landforms}, volume = {16}, year = {2014}, pages = {16840}, url = {www.submarineglacialatlas.com}, author = {Rebesco, Michele and Urgeles, Roger and {\"O}zmaral, Asli and Hanebuth, Till and Caburlotto, Andrea} } @article {Papadopoulos2014, title = {{Historical and pre-historical tsunamis in the Mediterranean and its connected seas: Geological signatures, generation mechanisms and coastal impacts}}, journal = {Marine Geology}, volume = {354}, year = {2014}, pages = {81{\textendash}109}, publisher = {Elsevier}, abstract = {The origin of tsunamis in the Mediterranean region and its connected seas, including the Marmara Sea, the Black Sea and the SW Iberian Margin in the NE Atlantic Ocean, is reviewed within the geological and seismotectonic settings of the region. A variety of historical documentary sources combined with evidence from onshore and offshore geological signatures, geomorphological imprints, observations from selected coastal archeological sites, as well as instrumental records, eyewitnesses accounts and pictorial material, clearly indicate that tsunami sources both seismic and non-seismic (e.g. volcanism, landslides) can be found in all the seas of the region with a variable tsunamigenic potential. Local, regional and basin-wide tsunamis have been documented. An improved map of 22 main tsunamigenic zones and their relative potential for tsunami generation is presented. From west to east, the most important tsunamigenic zones are situated offshore SW Iberia, in the North Algerian margin, in the Tyrrhenian Calabria and Messina Straits, in the western and eastern segments of the Hellenic Arc, in the Corinth Gulf of Central Greece, in the Levantine Sea offshore the Dead Sea Transform Fault and in the eastern side of the Marmara Sea. Important historical examples, including destructive tsunamis associated with large earthquakes, are presented. The mean recurrence of strong tsunamis in the several basins varies greatly but the highest event frequency (1/96. years) is observed in the east Mediterranean basin. For most of the historical events it is still unclear which was the causative seismic source and if the tsunami was caused by co-seismic slip, by earthquake-triggered submarine landslides or by a combination of both mechanisms. In pre-historical times, submarine volcanic eruptions (i.e. caldera collapse, massive pyroclastic flows, volcanogenic landslides) and large submarine landslides caused important tsunamis although little is known about their source mechanisms. We conclude that further investigation of the tsunami generation mechanisms is of primary importance in the Mediterranean region. Inputs from tsunami numerical modeling as well as from empirical discrimination criteria for characterizing tsunami sources have been proved particularly effective for recent, well-documented, aseismic landslide tsunamis (e.g., 1963 Corinth Gulf, 1979 C{\^O}te d{\textquoteright}Azur, 1999 Izmit Bay, 2002 Stromboli volcano). Since the tsunami generation mechanisms are controlled by a variety of factors, and given that the knowledge of past tsunami activity is the cornerstone for undertaking tsunami risk mitigation action, future interdisciplinary research efforts on past tsunamis are needed. {\textcopyright} 2014 Elsevier B.V.}, keywords = {Geological signatures, Historical tsunamis, Mediterranean region, Tsunami impact, Tsunami mechanisms}, issn = {00253227}, doi = {10.1016/j.margeo.2014.04.014}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84901663041\&partnerID=tZOtx3y1}, author = {Papadopoulos, Gerassimos A. and Gr{\'a}cia, Eul{\`a}lia and Urgeles, Roger and Sallares, Valenti and De Martini, Paolo Marco and Pantosti, Daniela and Gonz{\'a}lez, Mauricio and Yalciner, Ahmet C. and Mascle, Jean and Sakellariou, Dimitris and Salamon, Amos and Tinti, Stefano and Karastathis, Vassilis and Fokaefs, Anna and Camerlenghi, Angelo and Novikova, Tatyana and Papageorgiou, Antonia} } @article {Arroyo2014, title = {{Interplate seismicity at the CRISP drilling site: The 2002 Mw 6.4 Osa Earthquake at the southeastern end of the Middle America Trench}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {15}, number = {7}, year = {2014}, pages = {3035{\textendash}3050}, publisher = {Blackwell Publishing Ltd}, abstract = {We investigate potential relations between variations in seafloor relief and age of the incoming plate and interplate seismicity. Westward from Osa Peninsula in Costa Rica, a major change in the character of the incoming Cocos Plate is displayed by abrupt lateral variations in seafloor depth and thermal structure. Here a Mw 6.4 thrust earthquake was followed by three aftershock clusters in June 2002. Initial relocations indicate that the main shock occurred fairly trenchward of most large earthquakes along the Middle America Trench off central Costa Rica. The earthquake sequence occurred while a temporary network of OBH and land stations \~{}80 km to the northwest were deployed. By adding readings from permanent local stations, we obtain uncommon P wave coverage of a large subduction zone earthquake. We relocate this catalog using a nonlinear probabilistic approach within both, a 1-D and a 3-D P wave velocity models. The main shock occurred \~{}25 km from the trench and probably along the plate interface at 5-10 km depth. We analyze teleseismic data to further constrain the rupture process of the main shock. The best depth estimates indicate that most of the seismic energy was radiated at shallow depth below the continental slope, supporting the nucleation of the Osa earthquake at \~{}6 km depth. The location and depth coincide with the plate boundary imaged in prestack depth-migrated reflection lines shot near the nucleation area. Aftershocks propagated downdip to the area of a 1999 Mw 6.9 sequence and partially overlapped it. The results indicate that underthrusting of the young and buoyant Cocos Ridge has created conditions for interplate seismogenesis shallower and closer to the trench axis than elsewhere along the central Costa Rica margin. {\textcopyright} 2014. American Geophysical Union. All Rights Reserved.}, keywords = {earthquake relocation, erosional margin, interplate drilling}, issn = {15252027}, doi = {10.1002/2014GC005359}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84906266765\&partnerID=tZOtx3y1}, author = {Arroyo, Ivonne G. and Grevemeyer, Ingo and Ranero, Cesar R. and von Huene, Roland} } @book {Sassa2014, title = {{Landslide Science for a Safer Geoenvironment}}, volume = {2}, year = {2014}, pages = {483{\textendash}489}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, keywords = {ardizzone, cardinali f, f, fiorucci f, geological layers slip ellipsoid, GIS, guzzetti, i, marchesini m, santangelo m, slope stability open source}, isbn = {978-3-319-05049-2}, doi = {10.1007/978-3-319-05050-8}, url = {http://link.springer.com/10.1007/978-3-319-05050-8}, author = {Marchesini, Ivan and Mergili, Martin and Rossi, Mauro and Santangelo, Michele and Cardinali, Mauro and Ardizzone, Francesca and Fiorucci, Federica and Schneider-muntau, Barbara and Fellin, Wolfgang and Guzzetti, Fausto}, editor = {Sassa, Kyoji and Canuti, Paolo and Yin, Yueping} } @article {Cameselle2014, title = {{Late Miocene sedimentary architecture of the Ebro Continental Margin (Western Mediterranean): implications to the Messinian Salinity Crisis}}, journal = {International Journal of Earth Sciences}, volume = {103}, number = {2}, year = {2014}, pages = {423{\textendash}440}, keywords = {Ebro, Erosion, Mediterranean, Messinian, Miocene, Sea level}, issn = {1437-3254}, doi = {10.1007/s00531-013-0966-5}, url = {http://link.springer.com/10.1007/s00531-013-0966-5}, author = {Cameselle, Alejandra L and Urgeles, R and De Mol, B and Camerlenghi, Angelo and Canning, Jason C} } @booklet {GarciaX.MonteysX.EvansR.LandSzpak2014, title = {{Near seabed geology using a multidisciplinary geophysical approach in a shallow gas environment in the Malin Sea (NW Ireland)}}, year = {2014}, keywords = {accepted, Geochemistry, Geophysics, Geosystems}, author = {Garcia, X. and Monteys, X. and Evans, R.L and Szpak, M.T.} } @article {Neukirch2014, title = {{Nonstationary magnetotelluric data processing with instantaneous parameter}}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {119}, number = {3}, year = {2014}, pages = {1634{\textendash}1654}, issn = {21699313}, doi = {10.1002/2013JB010494}, url = {http://doi.wiley.com/10.1002/2013JB010494}, author = {Neukirch, M. and Garcia, X.} } @article {Roux2014, title = {{Optimizing an experimental design for a CSEM experiment: methodology and synthetic tests}}, journal = {Geophysical Journal International}, volume = {197}, number = {1}, year = {2014}, month = {jan}, pages = {135{\textendash}148}, abstract = {Optimizing an experimental design is a compromise between maximizing information we get about the target and limiting the cost of the experiment, providing a wide range of constraints. We present a statistical algorithm for experiment design that combines the use of linearized inverse theory and stochastic optimization technique. Linearized inverse theory is used to quantify the quality of one given experiment design while genetic algorithm (GA) enables us to examine a wide range of possible surveys. The particularity of our algorithm is the use of the multi-objective GA NSGA II that searches designs that fit several objective functions (OFs) simultaneously. This ability of NSGA II is helping us in defining an experiment design that focuses on a specified target area. We present a test of our algorithm using a 1-D electrical subsurface structure. The model we use represents a simple but realistic scenario in the context of CO2 sequestration that motivates this study. Our first synthetic test using a single OF shows that a limited number of well-distributed observations from a chosen design have the potential to resolve the given model. This synthetic test also points out the importance of a well-chosen OF, depending on our target. In order to improve these results, we show how the combination of two OFs using a multi-objective GA enables us to determine an experimental design that maximizes information about the reservoir layer. Finally, we present several tests of our statistical algorithm in more challenging environments by exploring the influence of noise, specific site characteristics or its potential for reservoir monitoring. {\textcopyright} The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, keywords = {Electrical properties, Inverse theory, Magnetotelluric}, issn = {0956-540X}, doi = {10.1093/gji/ggt525}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897848257\&partnerID=tZOtx3y1 http://gji.oxfordjournals.org/content/early/2014/01/29/gji.ggt525.short}, author = {Roux, E. and Garcia, X.} } @article {ferraterprimeros, title = {{PRIMEROS VALORES DE VELOCIDAD DE DESLIZAMIENTO LATERAL EN LA FALLA ALHAMA DE MURCIA BASADOS EN TRINCHERAS 3D}}, journal = {Segunda reuni{\'o}n Ib{\'e}rica sobre fallas activas y paleosismolog{\'\i}a}, year = {2014}, pages = {19}, author = {Ferrater, M and Ortu{\~n}o, M and Masana, E and Perea, H and Baize, S and Mart{\'\i}nez-D{\'\i}az, J J and Pall{\`a}s, R and Garc{\'\i}a-Mel{\'e}ndez, E} } @article {Biescas2014, title = {{Recovery of temperature, salinity, and potential density from ocean reflectivity}}, journal = {Journal of Geophysical Research: Oceans}, volume = {119}, number = {5}, year = {2014}, pages = {3171{\textendash}3184}, publisher = {Blackwell Publishing Ltd}, abstract = {This work explores a method to recover temperature, salinity, and potential density of the ocean using acoustic reflectivity data and time and space coincident expendable bathythermographs (XBT). The acoustically derived (vertical frequency >10 Hz) and the XBT-derived (vertical frequency <10 Hz) impedances are summed in the time domain to form impedance profiles. Temperature (T) and salinity (S) are then calculated from impedance using the international thermodynamics equations of seawater (GSW TEOS-10) and an empirical T-S relation derived with neural networks; and finally potential density ($\rho$) is calculated from T and S. The main difference between this method and previous inversion works done from real multichannel seismic reflection (MCS) data recorded in the ocean, is that it inverts density and it does not consider this magnitude constant along the profile, either in vertical or lateral dimension. We successfully test this method on MCS data collected in the Gulf of Cadiz (NE Atlantic Ocean). T, S, and $\rho$ are inverted with accuracies of $δ$Tsd=0.1C, $δ$Ssd=0.09, and $δ$$\rho$sd=0.02kg/m 3. Inverted temperature anomalies reveal baroclinic thermohaline fronts with intrusions. The observations support a mix of thermohaline features created by both double-diffusive and isopycnal stirring mechanisms. Our results show that reflectivity is primarily caused by thermal gradients but acoustic reflectors are not isopycnal in all domains. Key Points Recovery of oceanic T, S, and potential density from acoustic reflectivity data Thermal anomalies observations at the Mediterranean tongue level Comparison between acoustic reflectors in the ocean and isopycnals {\textcopyright} 2014. American Geophysical Union. All Rights Reserved.}, keywords = {low-frequency acoustic oceanography, ocean reflectivity, Seismic oceanography, thermohaline fronts, thermohaline intrusions}, issn = {21699275}, doi = {10.1002/2013JC009662}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84902770570\&partnerID=tZOtx3y1}, author = {Biescas, Berta and Ruddick, Barry R. and Nedimovic, Mladen R. and Sallares, Valenti and Bornstein, Guillermo and Mojica, Jhon F.} } @article {Dagnino2014, title = {{Scale- and parameter-adaptive model-based gradient pre-conditioner for elastic full-waveform inversion}}, journal = {Geophysical Journal International}, volume = {198}, number = {2}, year = {2014}, month = {jun}, pages = {1130{\textendash}1142}, publisher = {Oxford University Press}, abstract = {We present a scale- and parameter-adaptive method to pre-condition the gradient of the parameters to be inverted in time-domain 2-D elastic full-waveform inversion (FWI). The proposed technique, which relies on a change of variables of the model parameters, allows to balance the value of the gradient of the Lam{\'e} parameters and density throughout the model in each step of the multiscale inversion. The main difference compared to existing gradient pre-conditioners is that the variables are automatically selected based on a least squares minimization criteria of the gradient weight, which corresponds to the product of the gradient by a power of the parameter to be inverted. Based on numerical tests made with (1) a modified version of the Marmousi-2 model, and (2) a high-velocity and density local anomaly model, we illustrate that the value of the power helps to balance the gradient throughout the model. In addition, we show that a particular value exists for each parameter that optimizes the inversion results in terms of accuracy and efficiency. For the two models, the optimal power is \~{}2.0-2.5 and and \~{}1.5 for the first and second Lam{\'e} parameters, respectively; and between 3 and 6, depending on the inverted frequency, for density. These power values provide the fastest and most accurate inversion results for the three parameters in the framework of multiscale and multishooting FWI using three different optimization schemes. {\textcopyright} The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, keywords = {Computational seismology, Inverse theory, Numerical approximations and analysis, Seismic tomography}, issn = {0956-540X}, doi = {10.1093/gji/ggu175}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903949166\&partnerID=tZOtx3y1}, author = {Dagnino, D. and Sallar{\`e}s, V. and Ranero, C. R.} } @article {Martinez-Loriente2014, title = {{Seismic and gravity constraints on the nature of the basement in the Africa-Eurasia plate boundary: New insights for the geodynamic evolution of the SW Iberian margin}}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {119}, number = {1}, year = {2014}, month = {jan}, pages = {127{\textendash}149}, publisher = {Blackwell Publishing Ltd}, abstract = {We present a new classification of geological domains at the Africa-Eurasia plate boundary off SW Iberia, together with a regional geodynamic reconstruction spanning from the Mesozoic extension to the Neogene-to-present- day convergence. It is based on seismic velocity and density models along a new transect running from the Horseshoe to the Seine abyssal plains, which is combined with previously available geophysical models from the region. The basement velocity structure at the Seine Abyssal Plain indicates the presence of a highly heterogeneous, thin oceanic crust with local high-velocity anomalies possibly representing zones related to the presence of ultramafic rocks. The integration of this model with previous ones reveals the presence of three oceanic domains offshore SW Iberia: (1) the Seine Abyssal Plain domain, generated during the first stages of slow seafloor spreading in the NE Central Atlantic (Early Jurassic); (2) the Gulf of Cadiz domain, made of oceanic crust generated in the Alpine-Tethys spreading system between Iberia and Africa, which was coeval with the formation of the Seine Abyssal Plain domain and lasted up to the North Atlantic continental breakup (Late Jurassic); and (3) the Gorringe Bank domain, made of exhumed mantle rocks, which formed during the first stages of North Atlantic opening. Our models suggest that the Seine Abyssal Plain and Gulf of Cadiz domains are separated by the Lineament South strike-slip fault, whereas the Gulf of Cadiz and Gorringe Bank domains appear to be limited by a deep thrust fault located at the center of the Horseshoe Abyssal Plain. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {Central and North Atlantic kinematics, crustal nature, geological domains, gravity modeling, refraction and reflection traveltime tomography, wide-angle seismics}, issn = {21699313}, doi = {10.1002/2013JB010476}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84896782219\&partnerID=tZOtx3y1}, author = {Mart{\'\i}nez-Loriente, Sara and Sallares, Valenti and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, Nevio} } @inbook {GraciaE.BartolomeR.PereaH.MorenoX.GomezdelaPenaL.RaneroC.RLoIaconoC.Martinez-LorienteS.DiezS.MasanaE.Danobeitia2014, title = {{Seismic hazard of active faults in the Alboran Sea inferred from submarine paleosismology}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {101{\textendash}104}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {Gr{\`a}cia, E. and Bartolome, R. and Perea, H. and Moreno, X. and G{\'o}mez de la Pe{\~n}a, L. and Ranero, C.R and Lo Iacono, C. and Martinez-Loriente, S. and Diez, S. and Masana, E. and Da{\~n}obeitia, J.} } @article {Prada2014, title = {{Seismic structure of the Central Tyrrhenian basin: Geophysical constraints on the nature of the main crustal domains}}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {119}, number = {1}, year = {2014}, pages = {52{\textendash}70}, publisher = {Blackwell Publishing Ltd}, abstract = {In this work we investigate the crustal and tectonic structures of the Central Tyrrhenian back-arc basin combining refraction and wide-angle reflection seismic (WAS), gravity, and multichannel seismic (MCS) reflection data, acquired during the MEDOC (MEDiterr{\'a}neo OCcidental)-2010 survey along a transect crossing the entire basin from Sardinia to Campania at 40{\textdegree}N. The results presented include a \~{}450 km long 2-D P wave velocity model, obtained by the traveltime inversion of the WAS data, a coincident density model, and a MCS poststack time-migrated profile. We interpret three basement domains with different petrological affinity along the transect based on the comparison of velocity and velocity-derived density models with existing compilations for continental crust, oceanic crust, and exhumed mantle. The first domain includes the continental crust of Sardinia and the conjugate Campania margin. In the Sardinia margin, extension has thinned the crust from \~{}20 km under the coastline to \~{}13 km \~{}60 km seaward. Similarly, the Campania margin is also affected by strong extensional deformation. The second domain, under the Cornaglia Terrace and its conjugate Campania Terrace, appears to be oceanic in nature. However, it shows differences with respect to the reference Atlantic oceanic crust and agrees with that generated in back-arc oceanic settings. The velocities-depth relationships and lack of Moho reflections in seismic records of the third domain (i.e., the Magnaghi and Vavilov basins) support a basement fundamentally made of mantle rocks. The large seamounts of the third domain (e.g., Vavilov) are underlain by 10-20 km wide, relatively low-velocity anomalies interpreted as magmatic bodies locally intruding the mantle. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {back-arc crust, exhumed mantle, Rifting, traveltime tomography, Tyrrhenian basin, wide-angle seismics}, issn = {21699313}, doi = {10.1002/2013JB010527}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84896740908\&partnerID=tZOtx3y1}, author = {Prada, M. and Sallar{\`e}s, V. and Ranero, C. R. and Vendrell, M. G. and Grevemeyer, I. and Zitellini, N. and de Franco, R.} } @booklet {HensenC.ScholzF.MarianneN.ValadaresV.GraciaE.TerrinhaP.LiebetrauV.KaulN.SilvaS.Martinez-lorienteS.BartolomeR.PineroE.MagalhaesV.H.SchmidtM.WeiseS.M.CunhaM.HilarioA.Pereah.RovelliL.2014, title = {{Strike-slip Faults Mediate the Rise of Basement-Derived Fluids and Mud Volcanism in the Deep Sea}}, year = {2014}, keywords = {Geology}, author = {Hensen, C. and Scholz, F. and Marianne, N. and Valadares, V. and Gr{\`a}cia, E. and Terrinha, P. and Liebetrau, V. and Kaul, N. and Silva, S. and Martinez-Loriente, S. and Bartolome, R. and Pi{\~n}ero, E. and Mag{\~a}lhaes, V.H. and Schmidt, M. and S.M., Weise and Cunha, M. and Hilario, A. and Perea, H. and Rovelli, L. K.} } @article {LoIacono2014a, title = {{Submarine canyons of north-western Sicily (Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically active margin}}, journal = {Deep Sea Research Part II: Topical Studies in Oceanography}, volume = {104}, year = {2014}, month = {jun}, pages = {93{\textendash}105}, publisher = {Elsevier Ltd}, abstract = {Swath-bathymetry, mono-channel and multi-channel seismic reflection records acquired during the last two decades on the northern Sicilian margin have unveiled a dense network of submarine canyons within the depth range of 80-2100. m. The canyons display a relevant variability in their geometry, morphology and sedimentary processes. The margin shows a young, tectonically active shelf to slope setting, linking the Sicilian-Maghrebian Thrust Belt to the Tyrrhenian oceanic realm, developed during the Neogene-Quaternary time span. The aim of this study is to highlight the main governing factors that contributed to the evolution and differentiation of the northern Sicilian canyons, mainly focusing on the Gulf of Palermo and on the Gulf of Castellammare. Tectonic control is more evident in the canyons of the Gulf of Palermo, with submarine landslides retrograding on a steep slope and mainly controlling their evolution. Otherwise, canyons, tributaries and gullies mapped in the Gulf of Castellammare developed on a less steep substrate and display sinuous to meandering paths, with a relevant role of coastal/shelf sedimentary inputs and downslope turbidity processes in their formation. Results suggest that, despite the geographically close proximity of the two study areas, the different structural settings of the Castellammare and Palermo Basins are mainly responsible for canyon variability. Data indicate likely on-going uplift and tilting movements along the Sicilian margin, influencing the development of the studied canyons, which have probably been more active during the Quaternary glacial maxima than they are in the present day. {\textcopyright} 2013 Elsevier Ltd.}, keywords = {landslides, Seismic data, Sicily, Southern Tyrrhenian Sea, Submarine canyons, swath-bathymetry, tectonics}, issn = {09670645}, doi = {10.1016/j.dsr2.2013.06.018}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84901673777\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Sulli, Attilio and Agate, Mauro} } @inbook {LoIacono2014b, title = {{Submarine Mass Movements Along a Sediment Starved Margin: The Menorca Channel (Balearic Islands {\textendash} Western Mediterranean)}}, booktitle = {Submarine Mass Movements and Their Consequences}, year = {2014}, month = {mar}, pages = {329{\textendash}338}, publisher = {Springer International}, organization = {Springer International}, abstract = {The Malta-Sicily Escarpment (MSE) is a steep carbonate escarpment that appears to have largely remained isolated from inputs of fluvial and littoral sediments since the Messinian Salinity Crisis. Mass movement activity has so far only been inferred from sediment cores at the base of the MSE. In this study we use geophysical and sedimentological data acquired from the upper MSE and outer Malta Plateau to: (i) map and characterise the dominant forms of mass movements, and (ii) determine the nature and origin of these mass movements, and their role in the evolution of the MSE. We document 67 mass movement scars across 370 km2 of seafloor. Slope instability entailed translational slides, spreads and debris flows that mobilised Plio-Pleistocene outer shelf hemipelagic/pelagic sediments or carbonate sequences across the upper continental slope. Slope failure events are caused by loss of support associated with the formation of channels, gullies, canyon heads and fault-related escarpments. Mass movements play a key role in eroding the seafloor and transferring material to the lower MSE. In particular, they control the extent of headward and lateral extension of submarine canyons, facilitate tributary development, remove material from the continental shelf and slope, and feed sediment and drive its transport across the submarine canyon system.}, doi = {10.1007/978-3-319-00972-8\_29 ).}, url = {http://eprints.soton.ac.uk/362811/}, author = {Lo Iacono, Claudio and Urgeles, Roger and Polizzi, S. and Griny{\'o}, J. and Druet, M. and Agate, M. and Gili, J.M. and Acosta, J.} } @inbook {Torbahn2014a, title = {{Submarine Mass Movements and Their Consequences}}, booktitle = {Submarine Mass Movements and Their Consequences}, series = {Advances in Natural and Technological Hazards Research}, volume = {37}, year = {2014}, month = {jul}, pages = {85{\textendash}94}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {6th International Symposium on Submarine Mass Movements and Their Consequences (ISSMMTC), 23-25 September 2013, Kiel, Germany.{\textendash} 9 pages}, keywords = {Discrete element method, failure, mechanism, pore volume change, sediment fabric, sediment strength}, isbn = {978-3-319-00971-1}, doi = {10.1007/978-3-319-00972-8}, url = {http://link.springer.com/10.1007/978-3-319-00972-8}, author = {Torbahn, Lutz and Huhn, Katrin}, editor = {Krastel, Sebastian and Behrmann, Jan-Hinrich and V{\"o}lker, David and Stipp, Michael and Berndt, Christian and Urgeles, Roger and Chaytor, Jason and Huhn, Katrin and Strasser, Michael and Harbitz, Carl Bonnevie} } @inbook {PereaHGraciaE.BartolomeRMartinez-Loriente2014, title = {{Submarine paleoseismology on the Santa Pola fault (Bajo Segura basin, western mediterranean): derivating direct on-fault paleoearthquakes}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {121{\textendash}124}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {Perea, H and Gr{\`a}cia, E. and Bartolom{\'e}, R and Martinez-Loriente, S.} } @inbook {GomezdelaPenaL.RaneroC.R.GraciaE.BartolomeR.2014, title = {{T{\'e}cnicas avanzadas de procesado de datos de s{\'\i}smica de reflexi{\'o}n multicanal aplicadas a mejorar la visualizaci{\'o}n de fallas activas del Mar de Albor{\'a}n}}, booktitle = {Una aproximaci{\'o}n multidisciplinar al estudio de fallas activas, los terremotos y el riesgo s{\'\i}smico}, year = {2014}, pages = {229{\textendash}232}, isbn = {978-84-617-2049-1}, url = {http://www.researchgate.net/publication/267574309\_Una\_aproximacin\_multidisciplinar\_al\_estudio\_de\_las\_fallas\_activas\_los\_terremotos\_y\_el\_riesgo\_ssmico}, author = {G{\'o}mez de la Pe{\~n}a, L. and Ranero, C.R. and Gr{\`a}cia, E. and R., Bartolome and cruise Party, TopoMed} } @conference {Bartolome2014, title = {{TSUJAL project and marine survey: Crustal characterization of the Rivera Plate-Jalisco Block boundary and its implications for seismic and tsunami hazard assessment5) TSUJAL Working Group: D}}, booktitle = {2nd Iberian meeting on active faults and paleoseismology {\textendash} IBERFAULT 2014}, year = {2014}, month = {oct}, doi = {10.13140/2.1.3949.1524}, url = {http://www.researchgate.net/publication/267514007\_TSUJAL\_project\_and\_marine\_survey\_Crustal\_characterization\_of\_the\_Rivera\_Plate-Jalisco\_Block\_boundary\_and\_its\_implications\_for\_seismic\_and\_tsunami\_hazard\_assessment5)\_TSUJAL\_Working\}, author = {Bartolom{\'e}, R and Cordoba and Nu{\~n}ez-Corn{\'u} and Da{\~n}obeitia and Alonso, J.L. and Cameselle, A.L. and Castellon, A. and Estrada, F. and Perea, H. and Prada, M.} } @article {LoIacono2014316, title = {{The West Melilla cold water coral mounds, Eastern Alboran Sea: Morphological characterization and environmental context}}, journal = {Deep Sea Research Part II: Topical Studies in Oceanography}, volume = {99}, year = {2014}, pages = {316{\textendash}326}, abstract = {Abstract A new mound field, the West Melilla mounds, interpreted as being cold-water coral mounds, has been recently unveiled along the upper slope of the Mediterranean Moroccan continental margin, a few kilometers west of the Cape Tres Forcas. This study is based on the integration of high-resolution geophysical data (swath bathymetry, parametric sub-bottom profiler), \{CTD\} casts, Acoustic Doppler Current Profiler (ADCP), \{ROV\} video and seafloor sampling, acquired during the \{TOPOMED\} \{GASSIS\} (2011) and \{MELCOR\} (2012) cruises. Up to 103 mounds organized in two main clusters have been recognized in a depth range of 299{\textendash}590 m, displaying a high density of 5 mounds/km2. Mounds, 1{\textendash}48 m high above the surrounding seafloor and on average 260 m wide, are actually buried by a 1{\textendash}12 m thick fine-grained sediment blanket. Seismic data suggest that the West Melilla mounds grew throughout the Early Pleistocene{\textendash}Holocene, settling on erosive unconformities and mass movement deposits. During the last glacial{\textendash}interglacial transition, the West Melilla mounds may have suffered a drastic change of the local sedimentary regime during the late Holocene and, unable to stand increasing depositional rates, were progressively buried. At the present day, temperature and salinity values on the West Melilla mounds suggest a plausible oceanographic setting, suitable for live CWCs. Nonetheless, more data is required to groundtruth the West Melilla mounds and better constrain the interplay of sedimentary and oceanographic factors during the evolution of the West Melilla mounds.}, keywords = {Alboran Sea, high-resolution seismics, Quaternary, Swath mapping, \{CWC\} mounds}, issn = {0967-0645}, doi = {http://dx.doi.org/10.1016/j.dsr2.2013.07.006}, url = {http://www.sciencedirect.com/science/article/pii/S0967064513002786}, author = {Iacono, Claudio Lo and Gr{\'a}cia, Eul{\`a}lia and Ranero, C{\'e}sar R and Emelianov, Mikhail and Huvenne, Veerle A I and Bartolom{\'e}, Rafael and Booth-Rea, Guillermo and Prades, Javier and Ambroso, Stefano and Dominguez, Carlos and Griny{\'o}, Jordi and Rubio, Eduardo and Torrent, Josep} } @booklet {Ranero2014, title = {{The Western Mediterranean Pairs of Basin and Arc Systems}}, year = {2014}, month = {feb}, publisher = {Sociedad Geol{\'o}gica de Espa{\~n}a}, abstract = {Ranero, C{\'e}sar R. ... et. al.{\textendash} VIII Congreso Geol{\'o}gico de Espa{\~n}a, 2012, Oviedo}, isbn = {http://hdl.handle.net/10261/92021}, url = {http://digital.csic.es/handle/10261/92021}, author = {Ranero, Cesar R. and Gr{\'a}cia, Eul{\`a}lia and Sallares, Valenti and Garcia, Xavier and Gallart Muset, Josep and Bartolom{\'e}, Rafael and Lo Iacono, Claudio and Martinez-Loriente, S. and Moreno, Ximena and Prada, Manel and Perea, Hector and Zitellini, N.} } @article {Alcalde2013481, title = {{3-D reflection seismic imaging of the hontom{\'\i}n structure in the basque-cantabrian Basin (Spain)}}, journal = {Solid Earth}, volume = {4}, number = {2}, year = {2013}, pages = {481{\textendash}496}, abstract = {The Basque-Cantabrian Basin of the northern Iberia Peninsula constitutes a unique example of a major deformation system, featuring a dome structure developed by extensional tectonics followed by compressional reactivation. The occurrence of natural resources in the area and the possibility of establishing a geological storage site for carbon dioxide motivated the acquisition of a 3-D seismic reflection survey in 2010, centered on the Jurassic Hontom{\'\i}n dome. The objectives of this survey were to obtain a geological model of the overall structure and to establish a baseline model for a possible geological CO2 storage site. The 36 km2 survey included approximately 5000 mixed (Vibroseis and explosives) source points recorded with a 25 m inline source and receiver spacing. The target reservoir is a saline aquifer, at approximately 1450 m depth, encased and sealed by carbonate formations. Acquisition and processing parameters were influenced by the rough topography and relatively complex geology. A strong near-surface velocity inversion is evident in the data, affecting the quality of the data. The resulting 3-D image provides constraints on the key features of the geologic model. The Hontom{\'\i}n structure is interpreted to consist of an approximately 10 7 m2 large elongated dome with two major (W-E and NW-SE) striking faults bounding it. Preliminary capacity estimates indicate that about 1.2 Gt of CO2 can be stored in the target reservoir. {\textcopyright} 2013 Author(s).}, doi = {10.5194/se-4-481-2013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893313475\&partnerID=40\&md5=9d3f67fb71a49a58d6a7a48c1da54f43}, author = {Alcalde, J.a b and Mart{\'\i}, D.a and Juhlin, C.c and Malehmir, A.c and Sopher, D.c and Saura, E.a and Marz{\'a}n, I.a and Ayarza, P.d and Calahorrano, A.e and P{\'e}rez-Esta{\'u}n, A.a b and Carbonell, R.a} } @article {Martinez-Loriente2013, title = {{Active deformation in old oceanic lithosphere and significance for earthquake hazard: Seismic imaging of the Coral Patch Ridge area and neighboring abyssal plains (SW Iberian Margin)}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {7}, year = {2013}, month = {jul}, pages = {2206{\textendash}2231}, abstract = {Recently acquired high-resolution multichannel seismic profiles together with bathymetric and sub-bottom profiler data from the external part of the Gulf of Cadiz (Iberia-Africa plate boundary) reveal active deformation involving old (Mesozoic) oceanic lithosphere. This area is located 180 km offshore the SW Iberian Peninsula and embraces the prominent NE-SW trending Coral Patch Ridge, and part of the surrounding deep Horseshoe and Seine abyssal plains. E-W trending dextral strike-slip faults showing surface deformation of flower-like structures predominate in the Horseshoe Abyssal Plain, whereas NE-SW trending compressive structures prevail in the Coral Patch Ridge and Seine Hills. Although the Coral Patch Ridge region is characterized by subdued seismic activity, the area is not free from seismic hazard. Most of the newly mapped faults correspond to active blind thrusts and strike-slip faults that are able to generate large magnitude earthquakes (Mw 7.2-8.4). This may represent a significant earthquake and tsunami hazard that has been overlooked so far. Key Points New active structures have been mapped in the Coral Patch Ridge area The newly mapped faults are able to generate large magnitude earthquakes (Mw>7) These new structures may represent a significant earthquake and tsunami hazard {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {blind thrusts, fault-bend folds, Iberia-Africa boundary, multichannel seismics, seismic hazard assessment, strike-slip faults}, issn = {15252027}, doi = {10.1002/ggge.20173}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883575301\&partnerID=tZOtx3y1}, author = {Mart{\'\i}nez-Loriente, Sara and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Sallares, Valenti and Connors, Christopher and Perea, Hector and Lo Iacono, Claudio and Klaeschen, Dirk and Terrinha, Pedro and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, Nevio} } @conference {Garcia2013, title = {{ARMA 13-203 Revisiting Vertical Hydraulic Fracture Propagation Through Layered Formations {\textendash} A Numerical Evaluation}}, booktitle = {47th US Rock Mechanics/Geomechanics Symposium}, volume = {4}, year = {2013}, pages = {2501{\textendash}2511}, abstract = {In the oil and gas industry, vertical growth/containment of fractures during hydraulic fracturing is of pivotal importance to the success of well stimulations. Experimental work have improved our understanding of the topic, but it is sometimes difficult to explore, in isolation, some of the multiple parameters involved in the problem. Analytical models cannot account for the whole complexity of the problem, and although numerical models are an alternative, they also come with their own benefits and drawbacks. Oversimplification, limitations on the size of the treatable systems, and erroneous/doubtful assumptions are sometimes drawbacks of numerical approaches. In this work, an effort is made to overcome some of these issues and present a numerical model which incorporates the physics of fracture growth and does not rely on prescribed constitute laws or continuum equations. The approach is based on the discrete element method (DEM) and accounts for the physics of fracture growth from basic principles. The model has the benefit of being a hybrid model that includes the fine-details of tip mechanics plus the large-scale effects of an arbitrarily large surrounding medium. This approach was used to study, in isolation, the influence of toughness contrast on the propagation mode of a fracture through an interface separating two formations. The model captured the local scale effects of the interaction of the tip of a vertical fracture approaching a horizontal fracture while still being computationally efficient. The results obtained indicate that when varying the single parameter of toughness contrast, four main propagation modes were observed for Mode I fractures: straight crossing across the interface between layers, arrest at the interface, propagation across the interface but with a T-shaped fracture, and reinitiation of the fracture with an offset (jog). Copyright 2013 ARMA, American Rock Mechanics Association.}, isbn = {9781629931180}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84892878236\&partnerID=tZOtx3y1}, author = {Garcia, X and Nagel, N and Zhang, F and Lee, B} } @article {Gori2013, title = {{Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)}}, journal = {Biogeosciences}, volume = {10}, number = {3}, year = {2013}, month = {mar}, pages = {2049{\textendash}2060}, abstract = {Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze-Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony position with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large L. pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation (90{\textdegree} and 135{\textdegree} ) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general, no clear differences were observed in the abundance and in the size structure of the CWC populations between CCC and LDC, despite large differences in particulate matter between canyons. {\textcopyright} Author(s) 2013.}, issn = {1726-4189}, doi = {10.5194/bg-10-2049-2013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84880722043\&partnerID=tZOtx3y1}, author = {Gori, A. and Orejas, C. and Madurell, T. and Bramanti, L. and Martins, M. and Quintanilla, E. and Marti-Puig, P. and Lo Iacono, C. and Puig, P. and Requena, S. and Greenacre, M. and Gili, J. M.} } @article {DeJuan2013, title = {{Benthic habitat characterisation of soft-bottom continental shelves: Integration of acoustic surveys, benthic samples and trawling disturbance intensity}}, journal = {Estuarine, Coastal and Shelf Science}, volume = {117}, year = {2013}, month = {jan}, pages = {199{\textendash}209}, abstract = {Eleven sites were located on Mediterranean continental shelves to explore the link between the physical characteristics and epibenthic fauna from soft-sediment habitats. These sites, at 32-82 m in depth, were associated with fishing grounds and the trawling intensity was estimated at the site scale to assess the effects of trawling on benthic communities. Each site was surveyed with Multi-Beam (bathymetry and backscatter), side-scan sonar, benthic grabs and a surface dredge. The sites were clustered in three habitat types. Habitat 1, with moderate trawling disturbance, was characterised by homogeneous mud and associated epifauna that was also highly homogeneous across sites. Habitat 2, with sandy mud and scattered gravel and rocks, had a high abundance of sessile suspension feeders that probably attach to the coarser substratum and benefit from the low fishing disturbance in these sites. Habitat 3 included sites with heterogeneous sediments with ma{\"e}rl as the prevailing biocenosis and having the highest species richness, despite being subjected to variable trawling intensity. Statistical models were used to relate environmental parameters and the species abundance. More than 3 physical variables were necessary to explain the epifaunal patterns across sites, including the percentage of mud, sediment heterogeneity and fishing effort. These analyses are an essential step for extrapolating information from benthic samples to the larger scale of habitats, mapped through acoustic surveys. Despite this, a good integration is required between the mapping of physical habitat distribution and the ecological knowledge of communities. {\textcopyright} 2012 Elsevier Ltd.}, keywords = {benthic habitats, Continental shelf, Fishing disturbance, Mediterranean Sea, Multi-beam, Side-scan sonar}, issn = {02727714}, doi = {10.1016/j.ecss.2012.11.012}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84873710304\&partnerID=tZOtx3y1}, author = {de Juan, S. and Lo Iacono, C. and Demestre, M.} } @conference {Buffett2013, title = {{Characterization of thermohaline staircases in the Tyrrhenian Sea using stochastic heterogeneity mapping}}, booktitle = {Proceedings of Meetings on Acoustics}, volume = {19}, year = {2013}, pages = {005013{\textendash}005013}, abstract = {Processed multi-channel seismic (MCS) data acquired in the Tyrrhenian Sea in April-May 2010 provide images of oceanic thermohaline staircases. Using Stochastic Heterogeneity Mapping we characterize spatial reflector variations. This method is based on the band-limited von K{\'a}rm{\'a}n function. For scale sizes smaller than the correlation length, the von K{\'a}rm{\'a}n model describes a power law (fractal) process. We are most interested in the extraction of the exponent in the power law (The Hurst exponent) because it allows us to characterize the richness of scales present in the data set. Lower Hurst exponents represent a richer range of wavenumbers and therefore correspond to a broader range of heterogeneity in the observed seismic reflection events. The Hurst exponent is related to the fractal dimension and to the slope in the Garrett-Munk wavenumber spectrum. We interpret a richer range of heterogeneity as indicative of a greater degree of turbulent mixing. Data are presented alongside benchmark calibrations of synthetic seismic data generated from random fractal surfaces. We observe an oscillation in the Hurst exponent spectra as a function of frequency that is interpreted to represent a preferential coupling of energy across different spatial scales. {\textcopyright} 2013 Acoustical Society of America.}, issn = {1939800X}, doi = {10.1121/1.4799057}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84878961126\&partnerID=tZOtx3y1}, author = {Buffett, Grant G. and Hobbs, Richard W. and Vsemirnova, Ekaterina A. and Klaeschen, Dirk and Hurich, Charles A. and Ranero, César and Sallarès, Valentí} } @inbook {Masana2013a, title = {{Characterizing the seismic potential of the Eastern Betics Shear Zone (EBSZ), a major source of earthquakes in Southeastern Iberia}}, booktitle = {Contribuci{\'o}n de la Geolog{\'\i}a al An{\'a}lisis de la Peligrosidad S{\'\i}smica}, year = {2013}, month = {nov}, pages = {101{\textendash}104}, abstract = {Masana, E. ... et al.{\textendash} Primera Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a. Sig{\"u}enza, Guadalajara, Espa{\~n}a, 27-29 de Octubre de 2010.{\textendash} 4 pages, 1 figure}, isbn = {978-84-693-6088-0}, url = {http://hdl.handle.net/10261/82453}, author = {Masana, E. and Gr{\'a}cia, Eul{\`a}lia and Moreno, Ximena and Bartolom{\'e}, Rafael and Da{\~n}obeitia, Juan Jos{\'e}} } @article {Cameselle2013a, title = {{The continent-ocean transition of the Pearl River margin}}, journal = {AGU Fall Meeting Abstracts}, volume = {-1}, year = {2013}, month = {dec}, pages = {06}, abstract = {Rifted continental margins form by lithospheric extension and break-up. The continent to ocean transition (COT) architecture depends on the interplay between tectonic and magmatic processes, and thus, to study the COT variability of different systems is key to understand rifting. We use MCS data and magnetic lineations across the Pearl River margin (PRM) of South China Sea to investigate a previously poorly defined COT. The structure of the PRM presents different amounts of extension allowing the study of conjugate pairs of continental margins and their COT in a relative small region. We reprocessed about 2250 km of MCS data along 4 regional, crustal-scale lines and found that 3 of them possibly display the COT. The time-migrated seismic sections show differences in internal reflectivity, faulting style, fault-block geometry, the seismic character of the top of the basement, in the geometry of sediment deposits, and Moho reflections, that we interpret to represent clear continental and oceanic domains. The continental domain is characterized by arrays of normal faults and associated tilted blocks overlaid by syn-rift sedimentary units. The Moho is imaged as sub-horizontal reflections that define a fairly continuous boundary typically at 8-10 s TWT. Estimation of the thickness of the continental crust using 6 km/s average velocity indicates a \~{}22 km-thick continental crust under the uppermost slope passing abruptly to \~{}9-6 km under the lower slope. Comparatively the oceanic crust has a highly reflective top of basement, little-faulting, not discernible syn-tectonic strata, and fairly constant thick aness (4-8 km) defined by usually clear Moho reflections. The COT occurs across \~{}5-10 km narrow zone. Rifting resulted in asymmetric conjugate margins. The PRM shows arrays of tilted fault blocks covered by abundant syn-rift sediment, whereas the conjugate Macclesfield Bank margin displays abrupt thinning and little faulting. Seismic profiles also show a change in the tectonic structure from NE to SW. On the two NE- most lines, crustal thinning and break-up occur over 20-40 km wide segments. To the SW, continental extension occurred over a comparatively broader \~{}100-110 km segment of tilted fault-block structure. We interpret, that this 3D structural variability and the narrow COT was caused by the lateral NE to the SW propagation of a spreading center. In the NE, early spreading center propagation during ongoing rifting stopped continental stretching, causing an abrupt break-up and a narrow COT to seafloor spreading. Later arrival of spreading center propagated to the SW, resulted in a comparatively broader segment with fault-block structures of extended continental crust. However, the COT to clear oceanic crust is narrow. Spreading center propagation in the basin is however not a simple phenomena and ridge jumps and abrupt cessation of spreading contributed to form narrow COT that laterally change to highly thinned continental crust segments. We suggest that the tectonic architecture of continental extension and the abrupt COT along the PRM have been controlled by 3D oceanic spreading center propagation to a degree larger than by the local lithospheric structure during rifting.}, keywords = {8105 TECTONOPHYSICS Continental margins: divergent}, url = {http://adsabs.harvard.edu/abs/2013AGUFMOS23E..06C}, author = {Cameselle, Alejandra L. and Ranero, Cesar R. and Franke, Dieter and Barckhausen, Udo} } @article {Nagel2013, title = {{Coupled Numerical Evaluations of the Geomechanical Interactions Between a Hydraulic Fracture Stimulation and a Natural Fracture System in Shale Formations}}, journal = {Rock Mechanics and Rock Engineering}, volume = {46}, number = {3}, year = {2013}, month = {mar}, pages = {581{\textendash}609}, abstract = {Due to the low permeability of many shale reservoirs, multi-stage hydraulic fracturing in horizontal wells is used to increase the productive, stimulated reservoir volume. However, each created hydraulic fracture alters the stress field around it, and subsequent fractures are affected by the stress field from previous fractures. The results of a numerical evaluation of the effect of stress field changes (stress shadowing), as a function of natural fracture and geomechanical properties, are presented, including a detailed evaluation of natural fracture shear failure (and, by analogy, the generated microseismicity) due to a created hydraulic fracture. The numerical simulations were performed using continuum and discrete element modeling approaches in both mechanical-only and fully coupled, hydro-mechanical modes. The results show the critical impacts that the stress field changes from a created hydraulic fracture have on the shear of the natural fracture system, which in-turn, significantly affects the success of the hydraulic fracture stimulation. Furthermore, the results provide important insight into: the role of completion design (stage spacing) and operational parameters (rate, viscosity, etc.) on the possibility of enhancing the stimulation of the natural fracture network ({\textquoteright}complexity{\textquoteright}); the mechanisms that generate the microseismicity that occurs during a hydraulic fracture stimulation; and the interpretation of the generated microseismicity in relation to the volume of stimulated reservoir formation. {\textcopyright} 2013 Springer-Verlag Wien.}, keywords = {Discrete element modeling, Horizontal well, Hydraulic fracturing, Multi-stage fracturing, Natural fractures, Numerical simulation, Stimulation, Stimulation optimization, Well completion}, issn = {0723-2632}, doi = {10.1007/s00603-013-0391-x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84877873776\&partnerID=tZOtx3y1}, author = {Nagel, N. B. and Sanchez-Nagel, M. A. and Zhang, F. and Garcia, X. and Lee, B.} } @article {Rice2013, title = {{The Current Trajectory of Seismic Oceanography}}, journal = {Eos, Transactions American Geophysical Union}, volume = {94}, number = {36}, year = {2013}, month = {sep}, pages = {316{\textendash}316}, issn = {00963941}, doi = {10.1002/2013EO360003}, url = {http://doi.wiley.com/10.1002/2013EO360003}, author = {Rice, Ana E. and Ruddick, Barry R. and Biescas-Gorriz, Berta} } @article {Bornstein2013, title = {{Direct temperature and salinity acoustic full waveform inversion}}, journal = {Geophysical Research Letters}, volume = {40}, number = {16}, year = {2013}, month = {aug}, pages = {4344{\textendash}4348}, abstract = {Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed (c), density ($\rho$), temperature (T), and salinity (S) from the weak impedance contrasts associated with the ocean{\textquoteright}s thermohaline fine structure.The seismic inversion approaches proposed so far are based on the iterative inversion of c from multichannel seismic data, while the rest of parameters (T,S, and $\rho$) are determined in a second step using two equations of state and a local T-S empirical relationship. In this work, we present an alternative to this approach. Using 1-D synthetic seismic data, we demonstrate that the direct full waveform inversion of T and S using adjoint methods is feasible without the use of any local T-S relationship and that the models of physical properties obtained with this approach are far more accurate than those inferred from c. Key Points T and S can be inverted simultaneously from ocean acoustic data using FWI Local T-S empirical relationships are not required for the inversion Our T and S results have a potential density error of 0.01 kg/m3. {\textcopyright} 2013. American Geophysical Union. All Rights Reserved.}, keywords = {acoustic oceanography, adjoint method, full waveform inversion, thermohaline fine structure}, issn = {00948276}, doi = {10.1002/grl.50844}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84882307211\&partnerID=tZOtx3y1}, author = {Bornstein, G. and Biescas, B. and Sallar{\`e}s, V. and Mojica, J. F.} } @article {Moeller2013, title = {{Early-stage rifting of the northern Tyrrhenian Sea Basin: Results from a combined wide-angle and multichannel seismic study}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {8}, year = {2013}, month = {aug}, pages = {3032{\textendash}3052}, abstract = {Extension of the continental lithosphere leads to the formation of rift basins and ultimately may create passive continental margins. The mechanisms that operate during the early stage of crustal extension are still intensely debated. We present the results from coincident multichannel seismic and wide-angle seismic profiles that transect across the northern Tyrrhenian Sea Basin. The profiles cross the Corsica Basin (France) to the Latium Margin (Italy) where the early-rift stage of the basin is well preserved. We found two domains, each with a distinct tectonic style, heat flow and crustal thickness. One domain is the Corsica Basin in the west that formed before the main rift phase of the northern Tyrrhenian Sea opening (\~{}8-4 Ma). The second domain is rifted continental crust characterized by tilted blocks and half-graben structures in the central region and at the Latium Margin. These two domains are separated by a deep (\~{}10 km) sedimentary complex of the eastern portion of the Corsica Basin. Travel-time tomography of wide-angle seismic data reveals the crustal architecture and a subhorizontal 15-17 {\textpm} 1 km deep Moho discontinuity under the basin. To estimate the amount of horizontal extension we have identified the pre-, syn-, and post-tectonic sedimentary units and calculated the relative displacement of faults. We found that major faults initiated at angles of 45{\textdegree}-50{\textdegree} and that the rifted domain is horizontally stretched by a factor of $\beta$ \~{} 1.3 (\~{}8-10 mm/a). The crust has been thinned from \~{}24 to \~{}17 km indicating a similar amount of extension (\~{}30\%). The transect represents one of the best imaged early rifts and implies that the formation of crustal-scale detachments, or long-lived low-angle normal faults, is not a general feature that controls the rift initiation of continental crust. Other young rift basins, like the Gulf of Corinth, the Suez Rift or Lake Baikal, display features resembling the northern Tyrrhenian Basin, suggesting that half-graben formations and distributed homogeneous crustal thinning are a common feature during rift initiation. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {Basin formation, Continental extension, Multichannel seismic data, Rifting, Tyrrhenian Sea, Wide-Angle data}, issn = {15252027}, doi = {10.1002/ggge.20180}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84885100133\&partnerID=tZOtx3y1}, author = {Moeller, S. and Grevemeyer, I. and Ranero, C. R. and Berndt, C. and Klaeschen, D. and Sallar{\`e}s, V. and Zitellini, N. and de Franco, R.} } @article {Cartes2013, title = {{Geomorphological, trophic and human influences on the bamboo coral Isidella elongata assemblages in the deep Mediterranean: To what extent does Isidella form habitat for fish and invertebrates?}}, journal = {Deep Sea Research Part I: Oceanographic Research Papers}, volume = {76}, year = {2013}, month = {jun}, pages = {52{\textendash}65}, abstract = {We analyzed what are the best ecological conditions for megafauna associated with the bamboo coral Isidella elongata based on the geomorphological, physical and trophic information taken in 3 stations (St1, St2, St3) off the southern Catalonian coasts at 620m depth in June 2011. Results were compared with assemblage compositions recorded in past cruises (May 1992, 1994) at the same 3 stations. St1 was in a fishing ground exploited since the 1940s over a relatively wide slope at ca. 22km from the nearest canyon head; St2 and St3 were on a narrower slope closer to canyon heads and to the Ebro river mouth than St1. I. elongata had formed (to May 1994, at least) a dense coral forest at St2-St3 (to ca. 255 colonies/ha at St3), and some isolated colonies (to ca. 0.9 colonies/ha) were still collected in 2011. Fish and invertebrate communities significantly differed between St1 and St2/St3, with two macrourid fishes (Trachrhynchus trachyrhynchus and Nezumia aequalis) and two decapods (Plesionika martia and Plesionika acanthonotus) more abundant at St2/St3. The following ecological indicators imply better food conditions for megafauna at St2-St3 and for I. elongata itself: (i) greater density of zooplankton (copepods, euphausiids, and others) as potential prey for planktivores (including I. elongata); (ii) greater biomass and mean weight of epifaunal and infaunal deposit feeders; (iii) higher feeding intensity, F, at St3 for benthos feeders (Phycis blennoides, N. aequalis and Aristeus antennatus). Also, at St2-St3 we found higher near-bottom turbidity (indicating particle resuspension: food for suspension feeders) and finer and more reduced (Eh) sediments. The results let us suggest that corals and accompanying fauna preferently found optimal ecological conditions in the same habitat, while habitat-forming capacity by I. elongata seemed weak to generate these conditions. Coral forests may enhance detritus accumulations around them, improving habitat conditions for benthos feeders (e.g. macrourid fish). At St3 our side-scan sonar recorded three types of tracks produced by trawler doors, which match with three identified vessels occasionally operating in the area. After this low fishing activity off the Ebro Delta since the mid-1990s, almost all colonies of I. elongata has been removed. However, this impact has hardly altered fish and invertebrate composition without any significant loss of diversity, pointing also toward a rather low capacity of I. elongata facies in forming habitat for megafauna on muddy bottoms of the Mediterranean slope. {\textcopyright} 2013 Elsevier Ltd.}, keywords = {Bamboo coral, Canyons, Deep Mediterranean, Fish, Forming habitat, Invertebrates, Isidella elongate, Stable isotopy, Trophic relationships}, issn = {09670637}, doi = {10.1016/j.dsr.2013.01.006}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84876701226\&partnerID=tZOtx3y1}, author = {Cartes, J.E. and LoIacono, C. and Mamouridis, V. and L{\'o}pez-P{\'e}rez, C. and Rodr{\'\i}guez, P.} } @article {Kluesner2013, title = {{High density of structurally controlled, shallow to deep water fluid seep indicators imaged offshore Costa Rica}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {3}, year = {2013}, month = {mar}, pages = {519{\textendash}539}, abstract = {We used high-resolution mapping to document 161 sites of potential fluid seepage on the shelf and slope regions where no geophysical seep indicators had been reported. Identified potential seabed seepage sites show both high-backscatter anomalies and bathymetric expressions, such as pockmarks, mounds, and ridges. Almost all identified seabed features are associated with bright spots and flat spots beneath, as mapped within the 3-D seismic grid. We obtained EM122 multi-beam data using closely spaced receiver beams and 4-5 times overlapping multi-beam swaths, which greatly improved the sounding density and geologic resolvability of the data. At least one location shows an acoustic plume in the water column on a 3.5 kHz profile, and this plume is located along a fault trace and above surface and subsurface seepage indicators. Fluid indicators are largely associated with folds and faults within the sediment section, and many of the faults continue into and offset the reflective basement. A dense pattern of normal faults is seen on the outer shelf in the multi-beam bathymetry, backscatter, and 3-D seismic data, and the majority of fluid seepage indicators lie along mapped fault traces. Furthermore, linear mounds, ridges, and pockmark chains are found on the upper, middle, and lower slope regions. The arcuate shape of the shelf edge, projection of the Quepos Ridge, and high density of potential seep sites suggest that this area may be a zone of former seamount/ridge subduction. These results demonstrate a much greater potential seep density and distribution than previously reported across the Costa Rican margin. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {Costa Rica, fluid flow, fluid seepage, Marine Geology and Geophysics, subduction zones}, issn = {15252027}, doi = {10.1002/ggge.20058}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84879641763\&partnerID=tZOtx3y1}, author = {Kluesner, Jared W. and Silver, Eli A. and Bangs, Nathan L. and McIntosh, Kirk D. and Gibson, James and Orange, Daniel and Ranero, Cesar R. and von Huene, Roland} } @conference {BiescasGorriz2013, title = {{Inversion of density in the ocean from seismic reflection data}}, booktitle = {Proceedings of Meetings on Acoustics}, volume = {19}, year = {2013}, pages = {005009{\textendash}005009}, abstract = {Previous works in seismic oceanography explain that acoustic reflections are primarily associated with temperature vertical variations, so seismic images in the ocean can be interpreted as thermal contrasts maps. Temperature and salinity are the physical properties that describe structures in the ocean. However, the main physical parameter that controls oceans dynamics is the density and, since the ocean is a compressible fluid, potential density is the property that determines the stability, mixing and mesoscale motions of the particles. We have inverted oceanic impedance from seismic data and then derived density and potential density surfaces from the oceanic impedance. Results of the inverted potential density have been compared with seismic reflectors to show the relation between isopycnals and reflectors. We have also compare the seismic profiles of the GO Survey with the space-coincident CTDs and space and time-coincident XBTs to understand the nature of the reflectivity and its relation with the potential density in the ocean. {\textcopyright} 2013 Acoustical Society of America.}, issn = {1939800X}, doi = {10.1121/1.4798967}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84878986220\&partnerID=tZOtx3y1}, author = {Biescas Gorriz, Berta and Ruddick, Barry R. and Sallares, Valenti} } @article {Cameselle2013, title = {{Late Miocene sedimentary architecture of the Ebro Continental Margin (Western Mediterranean): implications to the Messinian Salinity Crisis}}, journal = {International Journal of Earth Sciences}, volume = {103}, number = {2}, year = {2013}, month = {nov}, pages = {423{\textendash}440}, abstract = {The Messinian Salinity Crisis (MSC) resulted from a significant multi-phase drop and subsequent reflooding of the Mediterranean Sea from 5.96 to 5.33 Ma. Well-developed drainage networks, characterized by step-like profiles and abrasion platforms, are associated to this event. The Ebro Continental Margin (Western Mediterranean) presents an additional complexity since the capture of the drainage of the adjacent subaerial Ebro Basin took place sometime prior to the Messinian stage. Using 3D seismic reflection data, this work provides new insights into the origin of the step-like profile of the Messinian erosional surface (MES) and timing of the capture of the subaerial Ebro Basin. The results obtained indicate a sedimentary-active continental slope and delta progradation during Middle-Late Miocene, in a normal regressive context associated to a pre-Messinian proto-Ebro River. The mature development attained by the Messinian Ebro River network during the MSC corroborates that the capture of the Ebro Basin occurred prior to the MSC. The configuration of the clinoforms below the MES suggests that deltaic sediments of the Messinian Paleo-Ebro River deposited during the Tortonian and initial Messinian sea-level drawdown. The MES formed at the top of the Tortonian Highstand, where a fluvial network was deeply carved, and in the topset region of the Messinian Falling Stage Systems Tract, where minor erosion occurred. Fluvial deposits are outstandingly preserved on the main valleys of the MES. Therefore, the step-like profile of the MES was not created during Zanclean inundation, but during the latest stages of the main Messinian sea-level fall and lowstand. {\textcopyright} 2013 Springer-Verlag Berlin Heidelberg.}, keywords = {Ebro, Erosion, Mediterranean, Messinian, Miocene, Sea level}, issn = {1437-3254}, doi = {10.1007/s00531-013-0966-5}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84894260158\&partnerID=tZOtx3y1}, author = {Cameselle, Alejandra L. and Urgeles, Roger and De Mol, Ben and Camerlenghi, Angelo and Canning, Jason C.} } @booklet {Volpi2013, title = {{Late Neogene to Recent seafloor instability on the deep Pacific margin of the Antarctic Peninsula}}, year = {2013}, month = {mar}, publisher = {SEPM (Society for Sedimentary Geology)}, abstract = {17 pages, 12 figures, 1 table}, keywords = {Antarctic Peninsula, contourite sedimentation, Pacific margin, Slope instability}, isbn = {isbn: 978-1-56576-287-9}, url = {http://digital.csic.es/handle/10261/72631}, author = {Volpi, Valentina and Amblas, David and Camerlenghi, Angelo and Canals, Miquel and Rebesco, M. and Urgeles, Roger} } @article {Miensopust2013, title = {{Magnetotelluric 3-D inversion{\textendash}a review of two successful workshops on forward and inversion code testing and comparison}}, journal = {Geophysical Journal International}, volume = {193}, number = {3}, year = {2013}, month = {mar}, pages = {1216{\textendash}1238}, abstract = {Over the last half decade the need for, and importance of, three-dimensional (3-D) modelling of magnetotelluric (MT) data have increased dramatically and various 3-D forward and inversion codes are in use and some have become commonly available. Comparison of forward responses and inversion results is an important step for code testing and validation prior to {\textquoteright}production{\textquoteright} use. The various codes use different mathematical approximations to the problem (finite differences, finite elements or integral equations), various orientations of the coordinate system, different sign conventions for the time dependence and various inversion strategies. Additionally, the obtained results are dependent on data analysis, selection and correction as well as on the chosen mesh, inversion parameters and regularization adopted, and therefore, a careful and knowledge-based use of the codes is essential. In 2008 and 2011, during two workshops at the Dublin Institute for Advanced Studies over 40 people from academia (scientists and students) and industry from around the world met to discuss 3-D MT inversion. These workshops brought together a mix of code writers as well as code users to assess the current status of 3-D modelling, to compare the results of different codes, and to discuss and think about future improvements and new aims in 3-D modelling. To test the numerical forward solutions, two 3-D models were designed to compare the responses obtained by different codes and/or users. Furthermore, inversion results of these two data sets and two additional data sets obtained from unknown models (secret models) were also compared. In this manuscript the test models and data sets are described (supplementary files are available) and comparisons of the results are shown. Details regarding the used data, forward and inversion parameters as well as computational power are summarized for each case, and the main discussion points of the workshops are reviewed. In general, the responses obtained from the various forward models are comfortingly very similar, and discrepancies are mainly related to the adopted mesh. For the inversions, the results show how the inversion outcome is affected by distortion and the choice of errors, as well as by the completeness of the data set. We hope that these compilations will become useful not only for those that were involved in the workshops, but for the entire MT community and also the broader geoscience community who may be interested in the resolution offered by MT. {\textcopyright} The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, keywords = {Geomagnetic induction, Inverse theory, Magnetotelluric, Numerical solutions}, issn = {0956-540X}, doi = {10.1093/gji/ggt066}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84879858225\&partnerID=tZOtx3y1}, author = {Miensopust, M. P. and Queralt, P. and Jones, A. G.} } @article {NEUKIRCH2013, title = {{NONSTATIONARY TIME SERIES CONVOLUTION: ON THE RELATION BETWEEN THE HILBERT{\textendash}HUANG AND FOURIER TRANSFORM}}, journal = {Advances in Adaptive Data Analysis}, volume = {05}, number = {01}, year = {2013}, month = {jan}, pages = {1350004}, publisher = {World Scientific Publishing Company}, abstract = {The Hilbert{\textendash}Huang Transform (HHT) decomposes time series into intrinsic mode functions (IMF) in time-frequency domain. We show that time slices of IMFs equal time slices of Fourier series, where the instantaneous parameters of the IMF define the parameters amplitude and phase of the Fourier series. This leads to the formulation of the theorem that nonstationary convolution of an IMF with a general time domain response function translates into a multiplication of the IMF with the respective spectral domain response function which is explicitly permitted to vary over time. We conclude and show on a real world application that a de-trended signal{\textquoteright}s IMFs can be convolved independently and then be used for further time-frequency analysis. Finally, a discussion is opened on parallels in HHT and the Fourier transform with respect to the time-frequency domain.}, keywords = {convolution, Fourier transform, Hilbert{\textendash}Huang transform, nonstationary, Time series}, issn = {1793-5369}, doi = {10.1142/S1793536913500040}, url = {http://www.worldscientific.com/doi/abs/10.1142/S1793536913500040}, author = {NEUKIRCH, MAIK and Garcia, Xavier} } @article {Mel{\'e}ndez2013243, title = {{Origin of water layer multiple phases with anomalously high amplitude in near-seafloor wide-angle seismic recordings}}, journal = {Geophysical Journal International}, volume = {196}, number = {1}, year = {2013}, pages = {243{\textendash}252}, abstract = {Water layer multiple seismic phases are recorded at ocean bottom seismometers and hydrophones as arrivals that correspond to the reflection of the primary phases at the sea-free air interface. In regions of low to moderate seabed relief, the shape of these phases mimics that of the primary phases with a traveltime delay that depends on the water layer thickness at the receiver location. Given their longer travel paths, multiple phases should have smaller amplitudes than their corresponding primary phases. However, depending on the geological context it can be relatively common to observe the opposite, which results in the identification of the multiple phases at longer offsets than the primary events. In this paper, we examine the origin of this apparently paradoxical phenomenon by analysing the combined effect of the major factors potentially involved: the source frequency content, the subsurface velocity distribution, the receiver-seafloor distance, the geometrical spreading and attenuation of sound waves and the ambient noise level.We use synthetic modelling to show that for certain combinations of these factors, the interference between the multiple and its reflection at the seafloor is constructive and has a higher amplitude than the primary wave. Our analysis indicates that in the most favourable cases the phases resulting from this interference can be observed at offsets some tens of kilometres longer than their corresponding primary phases, and thus they can provide useful information for velocity modelling. {\textcopyright} The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.}, keywords = {ambient noise, Controlled source seismology, Controlled-source seismologies, Earthquake effects, Geometrical spread, hydrophone, Numerical approximations and analysis, numerical method, ocea, Seismology, Site effects, Wave propagation}, issn = {0956540X}, doi = {10.1093/gji/ggt391}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84890885715\&partnerID=tZOtx3y1 http://www.scopus.com/inward/record.url?eid=2-s2.0-84890885715\&partnerID=40\&md5=a3729b5c20fafb9373a2a82c94b34990}, author = {Mel{\'e}ndez, A.a and Sallar{\`e}s, V.a and Ranero, C.R.b R. and Kormann, J.c and Mel{\'e}ndez, A. and Sallar{\`e}s, V.} } @article {Sallares2013a, title = {{Overriding plate structure of the Nicaragua convergent margin: Relationship to the seismogenic zone of the 1992 tsunami earthquake}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {14}, number = {9}, year = {2013}, month = {sep}, pages = {3436{\textendash}3461}, abstract = {We present 2-D seismic velocity models and coincident multichannel seismic reflection images of the overriding plate and the inter-plate boundary of the Nicaragua convergent margin along two wide-angle seismic profiles parallel and normal to the trench acquired in the rupture area of the 1992 tsunami earthquake. The trench-perpendicular profile runs over a seamount subducting under the margin slope, at the location where seismological observations predict large coseismic slip. Along this profile, the igneous basement shows increasing velocity both with depth and away from the trench, reflecting a progressive decrease in upper-plate rock degree of fracturing. Upper mantle-like velocities are obtained at \~{}10 km depth beneath the fore-arc Sandino basin, indicating a shallow mantle wedge. A mismatch of the inter-plate reflector in the velocity models and along coincident multichannel seismic profiles under the slope is best explained by \~{}15\% velocity anisotropy, probably caused by subvertical open fractures that may be related to fluid paths feeding known seafloor seepage sites. The presence of a shallow, partially serpentinized mantle wedge, and the fracture-related anisotropy are supported by gravity analysis of velocity-derived density models. The downdip limit of inter-plate seismicity occurs near the tip of the inferred mantle wedge, suggesting that seismicity could be controlled by the presence of serpentinite group minerals at the fault gouge. Near the trench, the inferred local increase of normal stress produced by the subducting seamount in the plate boundary may have made this fault segment unstable during earthquake rupture, which could explain its tsunamigenic character. {\textcopyright} 2013. American Geophysical Union. All Rights Reserved.}, keywords = {Convergent margin, travel time tomography, tsunami earthquake, wide-angle seismics}, issn = {15252027}, doi = {10.1002/ggge.20214}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84886671506\&partnerID=tZOtx3y1}, author = {Sallares, Valenti and Mel{\'e}ndez, Adri{\`a} and Prada, Manuel and Ranero, Cesar R. and McIntosh, Kirk and Grevemeyer, Ingo} } @article {Lucchi2013, title = {{Postglacial sedimentary processes on the Storfjorden and Kveithola trough mouth fans: Significance of extreme glacimarine sedimentation}}, journal = {Global and Planetary Change}, volume = {111}, year = {2013}, month = {dec}, pages = {309{\textendash}326}, abstract = {The depositional history of the Storfjorden and Kveithola trough-mouth fans (TMFs) in the northwestern Barents Sea has been investigated within two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS. The investigation has been conducted using a multidisciplinary approach to the study of sediment cores positioned on high-resolution multibeam bathymetry and TOPAS/CHIRP sub-bottom profiles.Core correlation and the age model were based on 27 AMS 14C samples, rock magnetic parameters, lithofacies sequences, and the presence of marker beds including two oxidized layers marking the post Last Glacial Maximum (LGM) inception of deglaciation (OX-2) and the Younger Dryas cold climatic event (OX-1).Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream dynamics and oceanographic patterns in response to climate change. The glacigenic diamicton with low water content, high density, and high shear strength, deposited during glacial maxima, indicates ice streams grounded at the shelf edge. Massive release of IRD occurred at the inception of deglaciation in response to increased calving rates with possible outer ice streams lift off and collapse. The presence of a several-meter-thick sequence of interlaminated sediments deposited by subglacial outbursts of turbid meltwater (plumites) indicates rapid ice streams{\textquoteright} melting and retreat. Crudely-layered and heavily-bioturbated sediments were deposited by contour currents under climatic/environmental conditions favorable to bioproductivity.The extreme sedimentation rate of 3.4cma-1 calculated for the plumites from the upper-slope area indicates a massive, nearly instantaneous (less than 150years), terrigenous input corresponding to an outstanding meltwater event. We propose these interlaminated sediments to represent the high-latitude marine record of MeltWater Pulse 1a (MWP-1a). Different bathymetric and oceanographic conditions controlled locally the mode of glacial retreat, resulting in different thickness of plumites on the upper continental slope of the Storfjorden and Kveithola TMFs. It is possible that the southern part of Storfjorden TMF received additional sediments from the deglaciation of the neighboring Kveithola ice stream. {\textcopyright} 2013.}, keywords = {Barents Sea, Gullies, LGM, Meltwater plumes, MWP-1a, Sedimentary processes}, issn = {09218181}, doi = {10.1016/j.gloplacha.2013.10.008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84887563264\&partnerID=tZOtx3y1}, author = {Lucchi, R.G. and Camerlenghi, A. and Rebesco, M. and Colmenero-Hidalgo, E. and Sierro, F.J. and Sagnotti, L. and Urgeles, R. and Melis, R. and Morigi, C. and B{\'a}rcena, M.-A. and Giorgetti, G. and Villa, G. and Persico, D. and Flores, J.-A. and Rigual-Hern{\'a}ndez, A.S. and Pedrosa, M.T. and Macri, P. and Caburlotto, A.} } @article {E.Gracia2013, title = {{Preface: Marine and Lake Paleoseismology}}, journal = {Natural Hazards and Earth System Science}, volume = {13}, number = {12}, year = {2013}, month = {dec}, pages = {3469{\textendash}3478}, abstract = {This special issue of Natural Hazards and Earth System Sciences (NHESS) contains 16 papers that resulted from the European Science Foundation (ESF) Research Conference "Submarine Paleoseismology: The Offshore Search of Large Holocene Earthquakes" that was held at the Universit{\"a}tszentrum Obergurgl (Austria), from 11 to 16 September 2010 (Pantosti et al., 2011). The conference enabled scientists from a number of existing lines of research to give an official start and international recognition to subaqueous paleoseismology. The scope of this Special Issue is built on the content of the ESF conference and includes different aspects of marine and lake paleoseismology. The 16 papers are separated into two main groups, namely, on-fault or off-fault paleoseismic studies. On-fault paleoseismology focuses on the observation, measurement and quantification of history of movements along the fault plane, where direct evidence of earthquake activity includes displacement of sediment strata and landforms such as seafloor scarps (Argnani et al., 2012; Beck et al., 2012; Gr{\`a}cia et al., 2012; Perea et al., 2012; Polonia et al., 2012). Off-fault paleoseismology uses the sedimentary record to identify deposits generated, directly or indirectly by seismic activity, such as mass-transport deposits, turbidites and tsunamites (Drab et al., 2012; Morey et al., 2013; Cattaneo et al., 2012; Gerardi et al., 2012; Goldfinger et al., 2013b; Langridge et al., 2012; Nelson et al., 2012; Patton et al., 2013; Pouderoux et al., 2012a; Smedile et al., 2012; Vacchi et al., 2012). {\textcopyright} 2013 Author(s).}, issn = {1684-9981}, doi = {10.5194/nhess-13-3469-2013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84891048700\&partnerID=tZOtx3y1}, author = {E. Gr{\`a}cia, E. and Lamarche, G. and Nelson, H. and Pantosti, D.} } @booklet {Martinez-Loriente2013a, title = {{Pre-stack depth migration seismic imaging of the Coral Patch Ridge and adjacent Horseshoe and Seine Abyssal Plains (Gulf of Cadiz): tectonic implications}}, year = {2013}, month = {apr}, publisher = {Universidad de Oviedo}, abstract = {Peer Reviewed}, url = {http://digital.csic.es/handle/10261/75234}, author = {Martinez-Loriente, S. and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Klaeschen, D. and Vizcaino, A. and Sallares, Valenti and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, N.} } @article {Sallares2013, title = {{Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia)}}, journal = {Earth and Planetary Science Letters}, volume = {365}, year = {2013}, month = {mar}, pages = {120{\textendash}131}, abstract = {The Gorringe Bank is a gigantic seamount that separates the Horseshoe and Tagus abyssal plains offshore SW Iberia, in a zone that hosts the convergent boundary between the Africa and Eurasia plates. Although the region has been the focus of numerous investigations since the early 1970s, the lack of appropriate geophysical data makes the nature of the basement, and thus the origin of the structures, still debated. In this work, we present combined P-wave seismic velocity and gravity models along a transect that crosses the Gorringe Bank from the Tagus to the Horseshoe abyssal plains. The P-wave velocity structure of the basement is similar in the Tagus and Horseshoe plains. It shows a 2.5-3.0. km-thick top layer with a velocity gradient twice stronger than oceanic Layer 2 and an abrupt change to an underlying layer with a five-fold weaker gradient. Velocity and density is lower beneath the Gorringe Bank probably due to enhanced fracturing, that have led to rock disaggregation in the sediment-starved northern flank. In contrast to previous velocity models of this region, there is no evidence of a sharp crust-mantle boundary in any of the record sections. The modelling results indicate that the sediment overlays directly serpentinite rock, exhumed from the mantle with a degree of serpentinization decreasing from a maximum of 70-80\% under the top of Gorringe Bank to less than 5\% at a depth of \~{}20. km. We propose that the three domains were originally part of a single serpentine rock band, of nature and possibly origin similar to the Iberia Abyssal Plain ocean-continent transition, which was probably generated during the earliest phase of the North Atlantic opening that followed continental crust breakup (Early Cretaceous). During the Miocene, the NW-SE trending Eurasia-Africa convergence resulted in thrusting of the southeastern segment of the exhumed serpentinite band over the northwestern one, forming the Gorringe Bank. The local deformation associated to plate convergence and uplift could have promoted pervasive rock fracturing of the overriding plate, leading eventually to rock disaggregation in the northern flank of the GB, which could be now a potential source of rock avalanches and tsunamis. {\textcopyright} 2013 Elsevier B.V.}, keywords = {Gravity modelling, Mantle exhumation, North Atlantic margin, Travel-time tomography, wide-angle seismics}, issn = {0012821X}, doi = {10.1016/j.epsl.2013.01.021}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84874491076\&partnerID=tZOtx3y1}, author = {Sallares, Valenti and Mart{\'\i}nez-Loriente, Sara and Prada, Manel and Gr{\'a}cia, Eul{\`a}lia and Ranero, C{\'e}sar and Gutscher, Marc-Andr{\'e} and Bartolom{\'e}, Rafael and Gailler, Audrey and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, Nevio} } @booklet {Bartolome2013, title = {{Seismic imaging of active faults in the Southern Alboran Sea (SE Iberian Margin): First results of the 2010 EVENT-DEEP cruise}}, year = {2013}, month = {sep}, abstract = {Primera Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a. Sig{\"u}enza (Guadalajara, Espa{\~n}a) 27, 28 y 29 de Octubre de 2010.{\textendash} 4 pages, 4 figures}, isbn = {isbn: 978-84-693-6088-0}, url = {http://digital.csic.es/handle/10261/82462}, author = {Bartolom{\'e}, Rafael and Gr{\'a}cia, Eul{\`a}lia and Lo Iacono, Claudio and Martinez-Loriente, S. and Moreno, Ximena and Perea, Hector and Masana, E. and Team, EVENT-DEEP} } @conference {Gutierrez2013, title = {{Statistical model of a signal of Raman spectroscopy: Detection}}, booktitle = {Symposium of Signals, Images and Artificial Vision - 2013: STSIVA - 2013}, year = {2013}, month = {sep}, pages = {1{\textendash}5}, publisher = {IEEE}, organization = {IEEE}, abstract = {Raman spectroscopy (RS) is a technique to find the spectral fingerprint of a material under study. To reach the spectrum, it is necessary to pass the acquired signal at the spectrometer by a bank of filters known as Raman signal{\textquoteright}s preprocessing system, which should eliminate all noise components accompanying the signal. The behavior of these noise components, and even the signal itself, are information that can be useful in order to optimize the system and to study the signal itself. This paper proposes a statistical model of Raman signal as the pre-processing system receives it, the signal{\textquoteright}s noise components and their statistical behavior, including its mathematical representation are presented. Additionally, it shows the results of the implementation of the simulation model leaving the door open for the validation, on which work is being done. The implementation of this model may be useful as an input signal for the optimization of the filter banks, since there are not always sufficient Raman signals for detailed study and development of filters for a specific signal under study. The model could also be used as a base for the study for systems using Raman spectroscopy to recognize substances. {\textcopyright} 2013 IEEE.}, keywords = {pre-processing system of the Raman signal, Raman spectrometry, spectral fingerprint, statistical model}, isbn = {978-1-4799-1121-9}, doi = {10.1109/STSIVA.2013.6644935}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84891057081\&partnerID=tZOtx3y1}, author = {Gutierrez, Carlos A. and Garcia, Xavier and Zurek, Eduardo E. and Salazar, Augusto} } @article {Urgeles2013, title = {{Submarine landslides of the Mediterranean Sea: Trigger mechanisms, dynamics, and frequency-magnitude distribution}}, journal = {Journal of Geophysical Research: Earth Surface}, volume = {118}, number = {4}, year = {2013}, month = {dec}, pages = {2600{\textendash}2618}, publisher = {Blackwell Publishing Ltd}, abstract = {Submarine landslides are ubiquitous along Mediterranean continental margins. With the aim of understanding mass-wasting processes and related hazard at the scale of a large marine basin encompassing multiple geological settings, we have compiled data on their geometry, age, and trigger mechanism with a geographic information system. The distribution of submarine landslides in the Mediterranean reveals that major deltaic wedges have a higher density of large submarine landslides, while tectonically active margins are characterized by relatively small failures. In all areas, landslide size distributions display power law scaling for landslides > 1 km3. We find consistent differences on the exponent of the power law (${\th}eta$) depending on the tectonic setting. Available age information suggests that failures exceeding 1000 km3 are infrequent and may recur every \~{}40 kyr. Smaller failures that can still cause significant damage might be relatively frequent (failures > 1 km3 may recur every 40 years). The database highlights that our knowledge of submarine landslide activity with time is limited to a few tens of thousands of years. Available data suggest that submarine landslides may preferentially occur during lowstand periods, but no firm conclusion can be made on this respect, as only 70 landslides (out of 696 in the database) have relatively accurate age determinations. The temporal pattern and changes in frequency-magnitude distribution suggest that sedimentation patterns and pore pressure development have had a major role in triggering slope failures and control the sediment flux from mass wasting to the deep basin. Key Points Comprehensive catalog of submarine landslides in the Mediterranean Sea Geologic setting controls flux of sediment from submarine landslides Consolidation and fluid flow largely control submarine landslide initiation {\textcopyright}2013. American Geophysical Union. All Rights Reserved.}, keywords = {frequency-magnitude, GIS, Mediterranean Sea, Submarine landslides, trigger mechanisms}, issn = {21699003}, doi = {10.1002/2013JF002720}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84892999015\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and Camerlenghi, Angelo} } @conference {Institut2013, title = {{Tu-02-13 TOMO3D - A New 3-D Joint Refraction and Reflection Travel-time Tomography Code for Active-source Seismic Data}}, booktitle = {Eage {\textquoteright}13}, year = {2013}, month = {jun}, pages = {10{\textendash}13}, abstract = {TOMO3D is a code for three-dimensional refraction and reflection travel-time tomography of wide-angle seismic data that inverts for the velocity field and the geometry of a reflector. Ray tracing is performed by a hybrid method combining the graph and bending methods, and the inversion is iteratively solved using an LSQR algorithm. We present a series of benchmark tests with synthetic data for the forward and inverse problems, as well as other more complex tests comparing inversions with refraction travel times only (i.e. first arrivals) to others with refraction and reflection travel times. The combination of refraction and reflection data increases ray coverage and thus velocity resolution, while allowing the determination of major geological interfaces, and reducing the velocity-depth trade-off.}, issn = {2214-4609}, doi = {10.3997/2214-4609.20130372}, url = {http://www.earthdoc.org/publication/publicationdetails/?publication=69247}, author = {Institut, a Mel{\'e}ndez and Ci{\`e}ncies, De and Ci{\`e}ncies, V Sallar{\`e}s Institut De and Icrea, C R Ranero} } @article {Gracia2012a, title = {{Acoustic and seismic imaging of the Adra Fault (NE Alboran Sea): in search of the source of the 1910 Adra earthquake}}, journal = {Natural Hazards and Earth System Science}, volume = {12}, number = {11}, year = {2012}, month = {nov}, pages = {3255{\textendash}3267}, publisher = {European Geosciences Union}, abstract = {Recently acquired swath-bathymetry data and high-resolution seismic reflection profiles offshore Adra (Almer{\'\i}a, Spain) reveal the surficial expression of a NW-SE trending 20 km-long fault, which we termed the Adra Fault. Seismic imaging across the structure depicts a sub-vertical fault reaching the seafloor surface and slightly dipping to the NE showing an along-axis structural variability. Our new data suggest normal displacement of the uppermost units with probably a lateral component. Radiocarbon dating of a gravity core located in the area indicates that seafloor sediments are of Holocene age, suggesting present-day tectonic activity. The NE Alboran Sea area is characterized by significant low-magnitude earthquakes and by historical records of moderate magnitude, such as the Mw Combining double low line 6.1 1910 Adra Earthquake. The location, dimension and kinematics of the Adra Fault agree with the fault solution and magnitude of the 1910 Adra Earthquake, whose moment tensor analysis indicates normal-dextral motion. The fault seismic parameters indicate that the Adra Fault is a potential source of large magnitude (Mw <= 6.5) earthquakes, which represents an unreported seismic hazard for the neighbouring coastal areas.{\textcopyright} 2013 IEEE.}, issn = {1684-9981}, doi = {10.5194/nhess-12-3255-2012}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84881091009\&partnerID=tZOtx3y1 http://digital.csic.es/handle/10261/64147}, author = {Gr{\`a}cia, E. and Bartolome, R. and Lo Iacono, C. and Moreno, X. and Stich, D. and Mart{\'\i}nez-Diaz, J. J. and Bozzano, G. and Martinez-Loriente, S. and Perea, H. and Diez, S. and Masana, E. and Danobeitia, J. J. and Tello, O. and Sanz, J. L. and Carre{\~n}o, E.} } @article {Perea2012a, title = {{An active zone characterized by slow normal faults, the northwestern margin of the Val{\`e}ncia trough (NE Iberia): a review}}, journal = {Journal of Iberian Geology}, volume = {38}, number = {1}, year = {2012}, month = {sep}, pages = {35{\textendash}57}, abstract = {The northwestern margin of the Valencia trough is an area of low strain characterized by slow normal faults and low to moderate seismicity. Since the mid 1990s this area has been the subject of a number of studies on active tectonic which have proposed different approaches to the location of active faults and to the calculation of the parameters that describe their seismic cycle. Fifty-six active faults have been found and a classification has been made in accordance with their characteristics: a) faults with clear evidence of large paleo-, historic or instrumental earthquakes (2/56); b) faults with evidence of accumulated activity during the Plio-Quaternary and with associated instrumental seismicity (7/56); c) faults with evidence of accumulated activity during the Plio-Quaternary and without associated instrumental seismicity (17/56); d) faults with associated instrumental seismicity and without evidence of accumulated activity during the Plio-Quaternary (30/56), and e) faults without evidence of activity or inactive faults. The parameters that describe the seismic cycle of these faults have been evaluated by different methods that use the geological data obtained for each fault except when paleoseismological studies were available. This classification can be applied to other areas with low slip faults because of the simplicity of the approaches adopted. This study reviews the different approaches proposed and describes the active faults located, highlighting the need a) to better understand active faults in slow strain zones through paleoseismological studies, and b) to include them in seismic hazard studies.}, keywords = {Active faults, Active tectonics, Iberian peninsula, Paleoseismology, Seismic cycle, Val{\`e}ncia trough}, issn = {1886-7995}, doi = {10.5209/rev\_JIGE.2012.v38.n1.39204}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861786693\&partnerID=tZOtx3y1}, author = {Perea, H. and Masana, E. and Santanach, P.} } @article {Alfaro2012, title = {{The Bajo Segura Fault Zone: Active blind thrusting in the Eastern Betic Cordillera (SE Spain)}}, journal = {Journal of Iberian Geology}, volume = {38}, number = {1}, year = {2012}, month = {sep}, pages = {287{\textendash}300}, abstract = {The Bajo Segura Fault Zone, located at the NE end of the Eastern Betic Shear Zone, has been the site of some of the most intense seismic activity on the Iberian Peninsula in the historical and instrumental time periods. This structure is an active blind fault that does not show any surface rupture. It is characterised by a set of ENE-WSW trending blind thrust faults that offset the Triassic basement and cause active folding of the Upper Miocene-Quaternary sedimentary cover. The main active structures of this fault zone are two ENE-WSW striking reverse blind faults, the Torremendo and the Bajo Segura Faults, and several secondary NW-SE striking dextral faults (San Miguel de Salinas, Torrevieja and Guardamar Faults). These structures continue offshore to the east. From geological, geomorphological and geodetic data, we obtain fault slip rates between 0.2 and 0.4 mm/yr, whereas other authors have proposed higher values ranging between 0.75 and 1 mm/yr. The fault zone can generate earthquakes with maximum estimated magnitudes (Mw) from 6.6 to 7.1 and has approximate recurrence intervals between 4.500 and 21.500 years.}, keywords = {Active blind thrust, Bajo segura fault, Eastern betic shear zone, Palaeoseismology, Slip rate}, issn = {1886-7995}, doi = {10.5209/rev\_JIGE.2012.v38.n1.39217}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861777780\&partnerID=tZOtx3y1}, author = {Alfaro, P. and Bartolom{\'e}, R and Borque, M.J. and Est{\'e}vez, A. and Garc{\'\i}a-Mayordomo, J. and Garc{\'\i}a-Tortosa, F.J. and Gil, A.J. and Gr{\`a}cia, E. and Lo Iacono, C. and Perea, H.} } @inbook {TMadurell;C.Orejas;S.Requena;A.Gori;A.Purroy;C.LoIacono;A.Sabates;C.Dominguez;JM.Gili2012, title = {{The benthic communities of the Cap de Creus Canyon}}, booktitle = {Mediterranean submarine canyons: ecology and governance}, year = {2012}, pages = {123{\textendash}132}, isbn = {978-2-8317-1469-1}, doi = {2831714699}, url = {http://books.google.com/books?hl=es\&lr=\&id=7oanUOft4cwC\&pgis=1}, author = {T Madurell and Orejas, C. and Requena, S. and Gori, A. and Purroy, A. and Iacono, C. Lo and Sabates, A. and Dominguez, C. and Gili, JM.} } @inbook {Urgeles2012, title = {{Distinguishing sediment bedforms from sediment deformation in prodeltas of the Mediterranean Sea.}}, booktitle = {Submarine Mass Movement and Their Consequences, Advances in Natural and Technological Hazards Research}, year = {2012}, pages = {233{\textendash}244}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, address = {Dordrecht}, abstract = {Most Mediterranean prodeltas show undulated sediments on the foresets of their Holocene wedges. These features have been described all along the Mediterranean and interpreted as either soft sediment deformation or, more recently, as sediment bedforms. We present a detailed analysis of these features using ultrahighresolution seismic and bathymetric data, as well as geotechnical information and hydrodynamic time series and hydrographic transects. We show that the characteristics of the sediment undulations (morphology and configuration of the reflections down section and between adjacent undulations) are incompatible with a genesis by sediment deformation. {\textcopyright} Springer Science+Business Media B.V. 2012.}, keywords = {Prodeltas, Sediment bedforms, slope failure, Undulated sediments}, isbn = {978-94-007-2161-6}, doi = {10.1007/978-94-007-2162-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904091924\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and Cattaneo, Antonio and Puig, Pere and Liquete, Camino and De Mol, Ben and Sultan, Nabil and Trincardi, Fabio}, editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael} } @article {Bartolome2012, title = {{Evidence for active strike-slip faulting along the Eurasia-Africa convergence zone: Implications for seismic hazard in the southwest Iberian margin}}, journal = {Geology}, volume = {40}, number = {6}, year = {2012}, month = {apr}, pages = {495{\textendash}498}, abstract = {New seismic imaging and seismotectonic data from the southwest Iberian margin, the site of the present-day boundary between the European and African plates, reveal that active strike slip is occurring along two prominent lineaments that have recently been mapped using multibeam bathymetry. Multichannel seismic and subbottom profiler images acquired across the lineaments show seafloor displacements and active faulting to depths of at least 10 km and of a minimum length of 150 km. Seismic moment tensors show predominantly WNW-ESE rightlateral strike-slip motion, i.e., oblique to the direction of plate convergence. Estimates of earthquake source depths close to the fault planes indicate upper mantle (i.e., depths of 40-60 km) seismogenesis, implying the presence of old, thick, and brittle lithosphere. The estimated fault seismic parameters indicate that the faults are capable of generating great magnitude (Mw >= 8.0) earthquakes. Such large events raise the concomitant possibility of slope failures that have the potential to trigger tsunamis. Consequently, our findings identify an unreported earthquake and tsunami hazard for the Iberian and north African coastal areas. {\textcopyright} 2012 Geological Society of America.}, issn = {0091-7613}, doi = {10.1130/G33107.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84862119131\&partnerID=tZOtx3y1}, author = {Bartolome, R. and Gr{\`a}cia, E. and Stich, D. and Martinez-Loriente, S. and Klaeschen, D. and de Lis Mancilla, F. and Lo Iacono, C. and Danobeitia, J. J. and Zitellini, N.} } @booklet {Urgeles2014, title = {{Fluid flow focusing in passive continental margins : Significance to submarine slope instability}}, year = {2012}, month = {feb}, pages = {73{\textendash}82}, publisher = {CRC Press}, abstract = {Comprises the Proceedings of the 11th International Symposium on Landslides and 2nd North American Symposium on Landslides, Banff, Alberta, Canada, 2-8 June 2012}, isbn = {9780415621236}, url = {http://digital.csic.es/handle/10261/90563}, author = {Urgeles, R} } @article {Szpak2012, title = {{Geophysical and geochemical survey of a large marine pockmark on the Malin Shelf, Ireland}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {13}, number = {1}, year = {2012}, month = {jan}, pages = {n/a{\textendash}n/a}, abstract = {Marine pockmarks are a specific type of seabed geological setting resembling craters or pits and are considered seabed surface expressions of fluid flow in the subsurface. A large composite pockmark on the Malin Shelf, off the northern coast of Ireland was surveyed and ground truthed to assess its activity and investigate fluid related processes in the subsurface. Geophysical (including acoustic and electromagnetic) data confirmed the subsurface presence of signatures typical of fluids within the sediment. Shallow seismic profiling revealed a large shallow gas pocket and typical gas related indicators such as acoustic blanking and enhanced reflectors present underneath and around the large pockmark. Sulphate profiles indicate that gas from the shallow reservoir has been migrating upwards, at least recently. However, there are no chimney structures observed in the sub-bottom data and the migration pathways are not apparent. Electromagnetic data show slightly elevated electrical conductivity on the edges of the pockmarks and a drop below regional levels within the confines of the pockmark, suggesting changes in physical properties of the sediment. Nuclear Magnetic Resonance (NMR) experiments were employed to characterize the organic component of sediments from selected depths. Very strong microbial signatures were evident in all NMR spectra but microbes outside the pockmark appear to be much more active than inside. These observations coincide with spikes in conductivity and the lateral gas bearing body suggesting that there is an increase in microbial activity and biomass when gas is present. Copyright 2012 by the American Geophysical Union.}, keywords = {electromagnetic, Malin Shelf, microbial, NMR, organic matter, pockmark}, issn = {15252027}, doi = {10.1029/2011GC003787}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84856247401\&partnerID=tZOtx3y1}, author = {Szpak, M. T. and Monteys, X. and O{\textquoteright}Reilly, S. and Simpson, A. J. and Garcia, X. and Evans, R. L. and Allen, C. C. R. and McNally, D. J. and Courtier-Murias, D. and Kelleher, B. P.} } @article {Gutscher2012, title = {{The Gibraltar subduction: A decade of new geophysical data}}, journal = {Tectonophysics}, volume = {574-575}, year = {2012}, month = {oct}, pages = {72{\textendash}91}, abstract = {The Gibraltar arc, spans a complex portion of the Africa-Eurasia plate boundary marked by slow oblique convergence and intermediate and deep focus seismicity. The seemingly contradictory observations of a young extensional marine basin surrounded by an arcuate fold-and-thrust belt, have led to competing geodynamic models (delamination and subduction). Geophysical data acquired in the past decade provide a test for these models and support a narrow east-dipping, subduction zone. Seismic refraction studies indicate oceanic crust below the western Gulf of Cadiz. Tomography of the upper mantle reveals a steep, east-dipping high P-wave velocity body, beneath Gibraltar. The anisotropic mantle fabric from SKS splitting shows arc-parallel "fast directions", consistent with toroidal flow around a narrow, westward retreating subducting slab. The accompanying WSW advance of the Rif-Betic mountain belt has constructed a thick pile of deformed sediments, an accretionary wedge, characterized by west-vergent thrust anticlines. Bathymetric swath-mapping images an asymmetric embayment at the deformation front where a 2. km high basement ridge has collided. Subduction has slowed significantly since 5. Ma, but deformation of recent sediments and abundant mud volcanoes suggest ongoing activity in the accretionary wedge. Three possible origins for this deformation are discussed; gravitational spreading, overall NW-SE convergence between Africa and Iberia and finally a WSW tectonic push from slow, but ongoing roll-back subduction. In the absence of arc volcanism and shallow dipping thrust type earthquakes, evidence in favor of present-day subduction can only be indirect and remains the object of debate. Continued activity of the subduction offers a possible explanation for great (M. >. 8.5) earthquakes known to affect the area, like the famous 1755 Great Lisbon earthquake. Recent GPS studies show SW motion of stations in N Morocco at velocities of 3-6. mm/yr indicating the presence of an independent block, a "Rif-Betic-Alboran" microplate, situated between Iberia and Africa. {\textcopyright} 2012 Elsevier B.V.}, keywords = {Accretionary wedge, Active deformation, earthquakes, Iberia, Roll-back subduction, Tethys oceanic lithosphere}, issn = {00401951}, doi = {10.1016/j.tecto.2012.08.038}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84867273669\&partnerID=tZOtx3y1}, author = {Gutscher, M.-A. and Dominguez, S. and Westbrook, G.K. and Le Roy, P. and Rosas, F. and Duarte, J.C. and Terrinha, P. and Miranda, J.M. and Graindorge, D. and Gailler, A. and Sallar{\`e}s, V. and Bartolome, R.} } @book {LoIacono2012b, title = {{The habitats of the Cap de Creus continental shelf and Cap de Creus Canyon, northwestern Mediterranean}}, series = {Seafloor Geomorphology as Benthic Habitat. GeoHab Atlas of seafloor geomorphic features and benthic habitats}, year = {2012}, pages = {457{\textendash}469}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {Continental shelves and submarine canyons represent peculiar environments that are geologically heterogenous on a small spatial scale (form hundreds to tens of meters) and therefore play a central role in increasing the ecosystem biodiversity. The Cap de Creus continental shelf and Cap de Creus canyon are located in the southernmost sector of the Gulf of Lions, in the northwestern Mediterranean. The Cap de Creus continental shelf contains sandy and muddy sediments and an abrupt morphology, with rocky outcrops, relict bioherms, erosive features, and planar bedforms. The Cap de Creus canyon breaches the shelf at a depth of 110 m and denotes a marked difference in the morphology between the northern and the southern flank, reflecting a different depositional regime. The most common substrates correspond to coarse and medium sands (28\%) and silty sediments (40\%). The most common megabenthic assemblages of the shelf correspond to the communities of "offshore detritic" (31.95\%) and "coastal terrigenous muds" (36.99\%), mostly dominated by sea pens, alcyonaceans, and ceriantharians. The northern flank of the Cap de Creus canyon is predominantly depositional, whereas the southern flank is erosional. Rocky outcrops provide the substratum for cold-water coral (CWC) communities{\textquoteright} development, in which the white coral Madrepora oculata is the most abundant species. {\textcopyright} 2012 Elsevier Inc. All rights reserved.}, keywords = {Continental shelf, Geomorphology, Habitat mapping, Northwestern Mediterranean, Submarine Canyon, swath bathymetry}, isbn = {9780123851406}, doi = {10.1016/B978-0-12-385140-6.00032-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883461551\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Orejas, Covadonga and Gori, Andrea and Gili, Josep Maria and Requena, Susana and Puig, Pere and Rib{\'o}, Marta} } @inbook {LoIacono2012, title = {{The habitats of the Chella Bank. Eastern Alboran Sea (Western Mediterranean)}}, booktitle = {Seafloor Geomorphology as Benthic Habitat: GeoHAB Atlas of Seafloor Geomorphic Features and Benthic Habitats.}, year = {2012}, pages = {681{\textendash}690}, publisher = {Elsevier}, organization = {Elsevier}, abstract = {This chapter provides the first characterization of the geomorphic features and benthic habitats of the Chella Bank, a flat-topped volcanic peak situated in the Eastern Alboran Sea, Western Mediterranean. The Chella Bank, also named "Seco de los Olivos," occurs along the upper slope of the Almeria Margin, showing a subcircular shape and covering a surface area of 100 km2 within a depth range of 70-700 m. High-resolution swath bathymetric mapping reveals three main large-scale morphological features on Chella Bank: the flat subhorizontal top and two main ridges, located to the west and to the east of the bank-top. Video tracks acquired in the area showed the occurrence of macrobenthic communities such as gorgonian assemblages (Callogorgia verticillata, Viminella flagellum), small patches of living cold-water corals (Madrepora oculata), and sponges (Fakelia ventilabrum). An automatic classification of multibeam data has been tested on the area as a predictive habitat mapping method, using backscatter characteristics (intensity, texture), and depth measurements as surrogate descriptors of the habitats recognized on the Chella Bank. The Chella Bank is one of the study areas of the LIFE-INDEMARES Project, which aims to contribute to the protection and sustainable use of the marine biodiversity in the Spanish seas. {\textcopyright} 2012 Elsevier Inc. All rights reserved.}, keywords = {Alboran Sea, Geomorphology, Habitat mapping, Seamounts, swath bathymetry, Western Mediterranean}, isbn = {9780123851406}, doi = {10.1016/B978-0-12-385140-6.00049-9}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84884425529\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Gr{\`a}cia, Eul{\`a}lia G. and Bartolom{\'e}, Rafael and Coiras, Enrique and Jose Da{\~n}obeitia, Juan and Acosta, Juan} } @conference {Nagel2012a, title = {{Hydraulic fracturing optimization for unconventional reservoirs - The critical role of the mechanical properties of the natural fracture network}}, booktitle = {Society of Petroleum Engineers - SPE Canadian Unconventional Resources Conference 2012, CURC 2012}, volume = {1}, year = {2012}, pages = {227{\textendash}237}, abstract = {The success of many shale plays depends on the optimal stimulation of natural fractures, and the characterization of the natural fracture systems is a key issue often leading to the construction of a discrete fracture network (DFN). The DFN chiefly consists of fracture spacing, fracture dip, and dip direction from numerous sources, and, in some cases, is matched to well test data allowing for the determination of hydraulic properties. However, a commonly missing component of natural fracture characterization, and the component most important to evaluating the coupled hydro-mechanical behavior of the fractures during a hydraulic fracture stimulation, is the evaluation of the mechanical behavior of the fractures. The important mechanical parameters of the fractures include: a) elastic properties such as shear and normal stiffness, which relate changes in pore pressure to changes in aperture; b) strength parameters such as cohesion and friction angle, which define when a fracture may shear and open; c) dilational properties, which relate fracture opening to shear slippage; d) fracture toughness, which determines the pressure required to extend a fracture; and e) initial aperture. In this paper, using a new, state-of-the-art, fully-coupled, 3D distinct element hydraulic fracturing simulator, mechanical fracture parameters were evaluated in a parametric study in order to determine their impact on the effectiveness of hydraulic fracture stimulations. Copyright 2012, Society of Petroleum Engineers.}, isbn = {9781622764884}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84875645702\&partnerID=tZOtx3y1}, author = {Nagel, Neal B. and Garcia, Xavier and Lee, Byungtark and Sanchez-Nagel, Marisela} } @inbook {Locat2012, title = {{IGCP 511: Submarine Mass Movements and Their Consequences (2005-2009)}}, booktitle = {Tales Set in Stone {\textendash} 40 Years of the International Geoscience Programme (IGCP)}, year = {2012}, month = {feb}, pages = {62{\textendash}66}, publisher = {Unesco}, organization = {Unesco}, abstract = {Peer Reviewed}, isbn = {isbn: 978-92-3-001036-2}, url = {http://digital.csic.es/handle/10261/90571}, author = {Locat, Jacques and Mienert, Juergen and Urgeles, Roger} } @article {LoIacono2012a, title = {{Large, deepwater slope failures: Implications for landslide-generated tsunamis}}, journal = {Geology}, volume = {40}, number = {10}, year = {2012}, month = {aug}, pages = {931{\textendash}934}, abstract = {Deepwater landslides are often underestimated as potential tsunami triggers. The North Gorringe avalanche (NGA) is a large (\~{}80 km3 and 35 km runout) newly discovered and deepwater (2900 m to 5100 m depth) mass failure located at the northern fl ank of Gorringe Bank on the southwest Iberian margin. Steep slopes and pervasive fracturing are suggested as the main preconditioning factors for the NGA, while an earthquake is the most likely trigger mechanism. Near-fi eld tsunami simulations show that a mass failure similar to the NGA could generate a wave >15 m high that would hit the south Portuguese coasts in \~{}30 min. This suggests that deepwater landslides require more attention in geo-hazard assessment models of southern Europe, as well as, at a global scale, in seismically active margins. {\textcopyright} 2012 Geological Society of America.}, issn = {0091-7613}, doi = {10.1130/G33446.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84868693659\&partnerID=tZOtx3y1}, author = {Lo Iacono, C. and Gr{\`a}cia, E. and Zaniboni, F. and Pagnoni, G. and Tinti, S. and Bartolome, R. and Masson, D. G. and Wynn, R. B. and Lourenco, N. and Pinto de Abreu, M. and Danobeitia, J. J. and Zitellini, N.} } @inbook {Gracia2012, title = {{A Margem Sul Portuguesa profunda}}, booktitle = {Geologia de Portugal}, year = {2012}, pages = {961{\textendash}987}, keywords = {Estratigrafia, Geologia regional, Margem Sul Portuguesa, Morfotect{\'o}nica, Sismotect{\'o}nica}, url = {http://repositorio.lneg.pt/handle/10400.9/2252}, author = {Gr{\'a}cia, Eul{\`a}lia and Gutscher, Marc-Andr{\'e} and Louren{\c c}o, Nuno and Abreu, M. P.} } @conference {Nagel2012b, title = {{A numerical evaluation of the geomechanical interactions between a hydraulic fracture stimulation and a natural fracture system}}, booktitle = {46th US Rock Mechanics / Geomechanics Symposium 2012}, volume = {3}, year = {2012}, pages = {1882{\textendash}1898}, abstract = {Due to the low permeability of many shale gas reservoirs, multi-stage hydraulic fracturing in horizontal wells is used to increase the stimulated volume. However, each created hydraulic fracture alters the stress field around it, and subsequent fractures are affected by the stress field from the previous fractures, which results in higher net pressures, smaller fracture widths, and diminished microseismic emissions. The results of a numerical evaluation of the effect of stress shadowing, as a function of natural fracture and geomechanical properties, are presented, including a detailed evaluation of natural fracture shear failure (and, by analogy, the microseismicity) due to a created hydraulic fracture using both continuum and discrete element modeling approaches. The results show the critical impact that a created hydraulic fracture has on the shear of the natural fracture system, which in-turn, significantly affects the success of the stimulation. Furthermore, the results provide important insight into the mechanisms that generate the microseismicity that occurs during a hydraulic fracture stimulation. Copyright 2012 ARMA, American Rock Mechanics Association.}, isbn = {9781622765140}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84873277033\&partnerID=tZOtx3y1}, author = {Nagel, N. B. and Sanchez-Nagel, M. A. and Garcia, X. and Lee, B.} } @inbook {Rebesco2012, title = {{One million years of climatic generated landslide events on the northwestern Barents Sea continental margin.}}, booktitle = {Submarine Mass Movement and Their Consequences, Advances in Natural and Technological Hazards Research}, year = {2012}, pages = {747{\textendash}756}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, address = {Dordrecht}, abstract = {Relatively recent, shallow landslides are imaged both on swath bathymetry, sub-bottom and multichannel seismic reflection (MCS) data from the upper-middle continental slope on the Storfjorden and Kveithola Trough Mouth Fans, NW Barents Sea margin. Giant paleo-landslide deposits, detected only by MCS profiles, are characterized by chaotic acoustic units up to about 250 m thick on the lower continental slope. The thickest, oldest landslide, dated between 1 and 0.8 Ma, took place just after the large-scale intensification of glaciation in the Barents Sea. The apparent spatial coincidence of landslides and channels with the boundary between the two fan systems, that are generated due to huge quantities of sediments transported to the continental slope by paleo-ice streams, suggests a common controlling climatic process for their development. Most probably the slides are related to the abundance of basal meltwater beneath the ice sheet, which in addition to determining ice stream motion and lubrication also influences the behavior of mass wasting processes. {\textcopyright} Springer Science+Business Media B.V. 2012.}, keywords = {Continental slope, NW barents sea margin, Sealloor morphology, Seismic reflection, Submarine landslide}, isbn = {978-94-007-2161-6}, doi = {10.1007/978-94-007-2162-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904105361\&partnerID=tZOtx3y1}, author = {Rebesco, Michele and Pedrosa, Maria T. and Camerlenghi, Angelo and Lucchi, Renata G. and Sauli, Chiara and De Mol, Ben and Madrussani, Gianni and Urgeles, Roger and Rossi, Giuliana and B{\"o}hm, Gualtiero}, editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael} } @inbook {Harders2012, title = {{An overview of the role of long-term tectonics and incoming plate structure on segmentation of submarine mass wasting phenomena along the Middle America Trench.}}, booktitle = {Submarine Mass Movements and Their Consequences - 5th International Symposium}, year = {2012}, pages = {391{\textendash}402}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, address = {Dordrecht}, abstract = {We study mass wasting along the Middle America Trench (MAT), a subduction zone dominated by tectonic erosion, using a comprehensive data set of seafloor relief. We integrate previous studies of long- Term tectonic processes to analyze how they influence the evolution of the slope structure and precondition the continental slope for mass wasting. We have used the distribution of an inventory of 147 slope failure structures along the MAT to discuss their relation to subduction erosion. We interpret that preconditioning of the slope by long- Term tectonics, interacts in a shorter- Term scale with features on the under- Thrusting oceanic plate to modulate the abundance and types of mass wasting phenomena. The complex origin of the incoming oceanic plate has produced abrupt lateral changes in plate age, crustal thickness, relief, and response to bending deformation at the trench, leading to its partitioning into six segments. We found that the continental-slope failure style and abundance are partitioned into six segments that spatially match the ocean plate segments. {\textcopyright} Springer Science+Business Media B.V. 2012.}, keywords = {Convergent margin, Subduction erosion, Submarine landslide}, isbn = {978-94-007-2161-6}, doi = {10.1007/978-94-007-2162-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904112373\&partnerID=tZOtx3y1}, author = {Harders, Rieka and Ranero, Cesar R. and Weinrebe, Wilhelm}, editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael} } @article {Garcia-Mayordomo2012, title = {{The Quaternary Active Faults Database of Iberia (QAFI v.2.0)}}, journal = {Journal of Iberian Geology}, volume = {38}, number = {1}, year = {2012}, month = {sep}, pages = {301{\textendash}318}, abstract = {The Quaternary Active Faults Database of Iberia (QAFI) is an initiative lead by the Institute of Geology and Mines of Spain (Instituto Geol{\'o}gico y Minero de Espa{\~n}a, IGME) for building a public repository of scientific data regarding faults having documented activity during the last 2.59 Ma (Quaternary). QAFI also addresses a need to transfer geologic knowledge to practitioners of seismic hazard and risk in Iberia by identifying and characterizing seismogenic fault-sources. QAFI is populated by the information freely provided by more than 40 Earth science researchers, storing to date a total of 262 records. In this article we describe the development and evolution of the database, as well as its internal architecture. Additionally, a first global analysis of the data is provided with a special focus on length and slip-rate fault parameters. Finally, the database completeness and the internal consistency of the data are discussed. Even though QAFI v.2.0 is the most current resource for calculating fault-related seismic hazard in Iberia, the database is still incomplete and requires further review.}, keywords = {Active fault, Iberia, Portugal, Quaternary, Seismic hazard, Spain}, issn = {1886-7995}, doi = {10.5209/rev\_JIGE.2012.v38.n1.39219}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861912592\&partnerID=tZOtx3y1}, author = {Garc{\'\i}a-Mayordomo, J. and Insua-Ar{\'e}valo, J.M. and Mart{\'\i}nez-D{\'\i}az, J.J. and Jim{\'e}nez-D{\'\i}az, A. and Mart{\'\i}n-Banda, R. and Mart{\'\i}n-Alfageme, S. and {\'A}lvarez-G{\'o}mez, J.A. and Rodr{\'\i}guez-Peces, M. and P{\'e}rez-L{\'o}pez, R. and Rodr{\'\i}guez-Pascua, M.A. and Masana, E. and Perea, H. and Mart{\'\i}n-Gonz{\'a}lez, F. and Giner-Robles, J. and Nemser, E.S. and Cabral, J.} } @article {Perea2012, title = {{Quaternary active tectonic structures in the offshore Bajo Segura basin (SE Iberian Peninsula {\textendash} Mediterranean Sea)}}, journal = {Natural Hazards and Earth System Science}, volume = {12}, number = {10}, year = {2012}, month = {oct}, pages = {3151{\textendash}3168}, abstract = {The Bajo Segura fault zone (BSFZ) is the northern terminal splay of the Eastern Betic shear zone (EBSZ), a large left-lateral strike-slip fault system of sigmoid geometry stretching more than 450 km from Alicante to Almera. The BSFZ extends from the onshore Bajo Segura basin further into the Mediterranean Sea and shows a moderate instrumental seismic activity characterized by small earthquakes. Nevertheless, the zone was affected by large historical earthquakes of which the largest was the 1829 Torrevieja earthquake (IEMS98 X). The onshore area of the BSFZ is marked by active transpressive structures (faults and folds), whereas the offshore area has been scarcely explored from the tectonic point of view. During the EVENT-SHELF cruise, a total of 10 high-resolution single-channel seismic sparker profiles were obtained along and across the offshore Bajo Segura basin. Analysis of these profiles resulted in (a) the identification of 6 Quaternary seismo-stratigraphic units bounded by five horizons corresponding to regional erosional surfaces related to global sea level lowstands; and (b) the mapping of the active sub-seafloor structures and their correlation with those described onshore. Moreover, the results suggest that the Bajo Segura blind thrust fault or the Torrevieja left-lateral strike-slip fault, with prolongation offshore, could be considered as the source of the 1829 Torrevieja earthquake. These data improve our understanding of present deformation along the BSFZ and provide new insights into the seismic hazard in the area. {\textcopyright} 2012. Author(s) CC Attribution 3.0 License.}, issn = {1684-9981}, doi = {10.5194/nhess-12-3151-2012}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84867926421\&partnerID=tZOtx3y1}, author = {Perea, H. and Gr{\`a}cia, E. and Alfaro, P. and Bartolome, R. and Lo Iacono, C. and Moreno, X. and Masana, E.} } @inbook {Lucchi2012, title = {{Recent submarine landslides on the continental slope of Storfjorden and Kveithola Trough-Mouth Fans (north west Barents Sea)}}, booktitle = {Submarine Mass Movements and Their Consequences, Advances in Natural and Technological Hazards Research, 34, Springer, Dordrecht (The Netherlands)}, year = {2012}, pages = {735{\textendash}745}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, address = {Dordrecht}, abstract = {Up to 12 submarine landslides retain a morphological evidence as concave amphitheater-like depressions of various sizes on the middle and upper slope of the Storfjorden and Kveithola Trough-Mouth Fans (TMFs), NW Barents Sea. The largest of them show lateral scarps 35-40 m high that reach the continental shelf edge and cover an area of at least 1,120 km2. Submarine landslides are translational, with headwall and laterals scarps clearly cut into Last Glacial Maximum debris flows deposits. The largest landslides seem to be rooted at the base of a terrigenous/hemipelagic sedimentary unit inferred to be of Middle Weichselian age (Marine Isotopic Stage 3). Stratigraphic, lithological and geotechnical observations suggest that the rapid deposition of a thick sequence of fine-grained, high water content interlaminate plumites is the most important controlling factors in the generation of submarine landslides on the southern Storfjorden and Kveithola TMFs. {\textcopyright} Springer Science+Business Media B.V. 2012.}, keywords = {Barents Sea, Debris flow, Ice stream, Kveithola, Storfjorden, Submarine landslide, Trough-mouth fans}, isbn = {978-94-007-2161-6}, doi = {10.1007/978-94-007-2162-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84904104155\&partnerID=tZOtx3y1}, author = {Lucchi, Renata G. and Pedrosa, Maria T. and Camerlenghi, Angelo and Urgeles, Roger and De Mol, Ben and Rebesco, Michele}, editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael} } @article {Lefeldt2012, title = {{Seismic evidence of tectonic control on the depth of water influx into incoming oceanic plates at subduction trenches}}, journal = {Geochemistry Geophysics Geosystems}, volume = {13}, number = {5}, year = {2012}, month = {may}, pages = {Q05013}, abstract = {Water transported by slabs into the mantle at subduction zones plays key roles in tectonics, magmatism, fluid and volatiles fluxes, and most likely in the chemical evolution of the Earth{\textquoteright}s oceans and mantle. Yet, incorporation of water into oceanic plates before subduction is a poorly understood process. Several studies suggest that plates may acquire most water at subduction trenches because the ocean crust and uppermost mantle there are intensely faulted caused by bending and/or slab pull, and display anomalously low seismic velocities. The low velocities are interpreted to arise from a combination of fluid-filled fractures associated to normal faulting and mineral transformation by hydration. Mantle hydration by transformation of nominally dry peridotite to water-rich serpentinite could potentially create the largest fluid reservoir in slabs and is therefore the most relevant for the transport of water in the deep mantle. The depth of fracturing by normal-fault earthquakes is usually not well constrained, but could potentially create deep percolation paths for water that might hydrate up to tens of kilometers into the mantle, restrained only by serpentine stability. Yet, interpretation of deep intraplate mineral alteration remains speculative because active-source seismic experiments have sampled only the uppermost few kilometers of mantle, leaving the depth-extent of anomalous velocities and their relation to faulting unconstrained. Here we use a joint inversion of active-source seismic data, and both local and regional earthquakes to map the three dimensional distribution of anomalous velocities under a seismic network deployed at the trench seafloor. We found that anomalous velocities are restrained to the depth of normal-fault micro-earthquake activity recorded in the network, and are considerably shallower than either the rupture depth of teleseismic, normal-fault earthquakes, or the limit of serpentine stability. Extensional micro-earthquakes indicate that each fault in the region slips every 2-3months which may facilitate regular water percolation. Deeper, teleseismic earthquakes are comparatively infrequent, and possibly do not cause significant fracturing that remains open long enough to promote alteration detectable with our seismic study. Our results show that the stability field of serpentine does not constrain the depth of potential mantle hydration. Copyright 2012 by the American Geophysical Union.}, keywords = {Bending, Microseismicity, Oceanic plates, serpentinization, Subduction zone, Water influx}, issn = {1525-2027}, doi = {10.1029/2012GC004043}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861357079\&partnerID=tZOtx3y1}, author = {Lefeldt, M. and Ranero, C. R. and Grevemeyer, I.} } @article {Sallares2012, title = {{The structure of the Tyrrhenian from integration of multichannel seismic images, wide-angle seismic data, and gravity modeling}}, journal = {Rendiconti Online Societa Geologica Italiana}, volume = {21}, year = {2012}, pages = {253{\textendash}254}, keywords = {Crustal structure, Tectonic structure, Tyrrhenian rifting}, author = {SALLARES, V and Ranero, C{\'e}sar R and Zitellini, N and Grevemeyer, I and Guzman, M and Prada, M and Moeller, S and R., De Franco and MEDOC Cruise Party} } @book {YamadaY.KawamuraK.IkeharaK.OgawaY.UrgelesR.MosherD.Chaytor2012, title = {{Submarine Mass Movement and Their Consequences, Advances in Natural and Technological Hazards Research}}, year = {2012}, isbn = {978-94-007-2161-6}, url = {http://download.springer.com/static/pdf/417/bok\%253A978-94-007-2162-3.pdf?auth66=1423826628\_566a545ac7b53078aef1bac73bad361e\&ext=.pdf}, author = {Yamada, Y. and Kawamura, K. and Ikehara, K. and Ogawa, Y. and Urgeles, R. and Mosher, D. and Chaytor, J. and M., Strasser} } @inbook {Yamada2012, title = {{Submarine Mass Movements and Their Consequences: An introduction.}}, booktitle = {Submarine Mass Movement and Their Consequences, Advances in Natural and Technological Hazards Research}, year = {2012}, pages = {1{\textendash}12}, publisher = {Springer Netherlands}, organization = {Springer Netherlands}, address = {Dordrecht}, isbn = {978-94-007-2161-6}, doi = {10.1007/978-94-007-2162-3}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903753314\&partnerID=tZOtx3y1}, author = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael}, editor = {Yamada, Yasuhiro and Kawamura, Kiichiro and Ikehara, Ken and Ogawa, Yujiro and Urgeles, Roger and Mosher, David and Chaytor, Jason and Strasser, Michael} } @article {Amblas2012, title = {{Survival of a submarine canyon during long-term outbuilding of a continental margin}}, journal = {Geology}, volume = {40}, number = {6}, year = {2012}, month = {apr}, pages = {543{\textendash}546}, abstract = {Net-depositional submarine canyons are common in continental slope strata, but how they survive and prograde on constructional margins is poorly understood. In this study we present field evidence for the coevolution of a submarine canyon and the adjacent continental slope. Using a three-dimensional seismic data cube that images the Ebro margin (northwest Mediterranean), we identify a preserved canyon on a middle Pleistocene paleosurface and relate it directly to its expression on the present-day seafloor. A subparallel stacking pattern of seismic reflectors, similar to that seen between prograding clinoforms in intercanyon areas, is observed between the modern and paleocanyon thalwegs. The concavity of the modern long profile differs from the convex-concave long profile on the middle Pleistocene surface, suggesting a long-term change in canyon sedimentation. We interpret this change as a shift to a canyon dominated by turbidity currents from one strongly influenced by the pattern of sedimentation that built the open-slope canyon interfluves. We find support for our interpretation in previous studies of the Ebro margin. {\textcopyright} 2012 Geological Society of America.}, issn = {0091-7613}, doi = {10.1130/G33178.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84864298406\&partnerID=tZOtx3y1}, author = {Amblas, D. and Gerber, T. P. and De Mol, B. and Urgeles, R. and Garcia-Castellanos, D. and Canals, M. and Pratson, L. F. and Robb, N. and Canning, J.} } @conference {Ranero2012, title = {{The tectonic structure of the Tyrrhenian Basin, a complex interaction among faulting and magmatism}}, booktitle = {Rendiconti Online Societa Geologica Italiana}, volume = {21}, number = {PART 1}, year = {2012}, pages = {251{\textendash}252}, keywords = {Crustal structure, Tectonic structure, Tyrrhenian rifting}, issn = {20358008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84872362909\&partnerID=tZOtx3y1}, author = {Ranero, C. R. and Sallar{\`e}s, V. and Zitellini, N. and Grevemeyer, I. and Guzman, M. and Prada, M. and Moeller, S. and de Franco, R.} } @article {Rosas2012, title = {{Thrust{\textendash}wrench interference between major active faults in the Gulf of Cadiz (Africa{\textendash}Eurasia plate boundary, offshore SW Iberia): Tectonic implications from coupled analog and numerical modeling}}, journal = {Tectonophysics}, volume = {548-549}, year = {2012}, month = {jun}, pages = {1{\textendash}21}, abstract = {Analog and numerical modeling experiments were carried out to investigate the tectonic interference between intersecting major active strike-slip and thrust faults in the Gulf of Cadiz (Africa-Eurasia plate boundary, offshore SW Iberia). The obtained results show that newly mapped tectonic features located in the fault intersection area (corner zone) consist mostly in oblique (dextral-reverse) faults that accommodate significant strain partitioning. Modeling of this corner-zone faults show that they have endured some degree of rotation, displaying successive evolving geometries and kinematics. Numerical modeling results further show that an interbedded shallow soft layer, accounting for a regional (Late Miocene) gravitational "Chaotic" unit, could explain the mild bathymetric expression of the fault pattern in the corner-zone. Moreover, a recognized depth discrepancy, between the (upper crust) interference fault-pattern and the (lithospheric mantle) seismicity, is interpreted as a manifestation of similar thrust-wrench tectonic interference at different lithospheric depths. Accordingly, an intermediate lower crust-upper mantle aseismic (i.e. softened) depth-domain could be explained by pervasive alteration/serpentinization, prompted by fluid percolation through fault-related fractures associated with the newly revealed corner zone fault-network. Overall obtained results reinforce the relevance of a thrust-wrench multi-rupture seismic scenario as the main cause for the moderate seismicity (Mw < 6.0) in the study area. {\textcopyright} 2012 Elsevier B.V.}, keywords = {Analog and numerical modeling, Fault interference, Gulf of Cadiz, Lithospheric mantle seismicity, Multi-rupture seismic hazards, Thrust-wrench tectonics}, issn = {00401951}, doi = {10.1016/j.tecto.2012.04.013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84862115104\&partnerID=tZOtx3y1}, author = {Rosas, F.M. and Duarte, J.C. and Neves, M.C. and Terrinha, P. and Silva, S. and Matias, L. and Gr{\`a}cia, E. and Bartolome, R.} } @booklet {Goldfinger, title = {{Turbidite Event History{\textemdash}Methods and Implications for Holocene Paleoseismicity of the Cascadia Subduction Zone}}, year = {2012}, publisher = {U. S. Geological Survey}, abstract = {Appendices. {\textendash} 170 pages, 64 figures, 13 tables.}, url = {http://digital.csic.es/handle/10261/66386}, author = {Goldfinger, Chris and Nelson, C. Hans and Morey, Ann E. and Johnson, Joel E. and Patton, Jason and Karabanov, Eugene and Guti{\'e}rrez-Pastor, Julia and Eriksson, Andrew T. and Gr{\'a}cia, Eul{\`a}lia and Dunhill, Gita and Enkin, Randolph J. and Dallimore, Audrey and Vallier, Tracy} } @conference {Nagel2012, title = {{Understanding "SRV": A numerical investigation of "wet" vs. "dry" microseismicity during hydraulic fracturing}}, booktitle = {Proceedings - SPE Annual Technical Conference and Exhibition}, volume = {4}, year = {2012}, pages = {3375{\textendash}3386}, abstract = {Effective monitoring of hydraulic fracturing stimulations is critical to their optimization, and the evaluation of field microseismic data is now commonly used in many of the active shale plays for this purpose. The concept of Stimulated Reservoir Volume (SRV), for example, is a common technique wherein the extent of the microseismic data is used to represent the size of the fluid drainage area for a fracture or well. A principal challenge with the interpretation of microseismic data - and its use to determine drainage area or some other metric for the success of the stimulation - is the understanding of the actual cause of the microseismicity itself. Basic geomechanics principles show that rock failure - the cause of microseismicity - is a result of changes in the in-situ effective stresses relative to a given rock strength. Effective stress - which is the stress acting on the rock matrix - may change either through a change in pore pressure (leading to {\textquoteright}wet{\textquoteright} microseismicity) or through a change in the total stress (leading to {\textquoteright}dry{\textquoteright} microseismicity). Dry microseismicity may occur well beyond the pressure field and be hydraulically disconnected from the wellbore. In this paper, we present the results of a numerical study of hydraulic fracturing-induced microseismicity using a discrete element code, where the mechanical behavior of the natural fractures is modeled explicitly, which allows for the quantitative evaluation of {\textquoteright}wet{\textquoteright} versus {\textquoteright}dry{\textquoteright} microseismicity. Copyright 2012, Society of Petroleum Engineers.}, isbn = {9781622764150}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84874038119\&partnerID=tZOtx3y1}, author = {Nagel, Neal B. and Garcia, Xavier and Nagel, Marisela Sanchez and Lee, Byungtark} } @article {Reston2011, title = {{The 3-D geometry of detachment faulting at mid-ocean ridges}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {12}, number = {7}, year = {2011}, month = {jul}, pages = {n/a{\textendash}n/a}, abstract = {Seismic images of Cretaceous slow spreading crust from the eastern Central Atlantic provide new constraints on the process of seafloor spreading and the importance of detachment faulting. The seismic depth sections image detachment faults that appear to have exhumed footwall massifs of similar geometry to massifs of plutonic and mantle rocks mapped at the present Mid-Atlantic Ridge. The detachments are consistent with the structure and microearthquakes of the Mid-Atlantic Ridge at 26{\textdegree}N, with the footwall rotation inferred from paleomagnetic data and with numerical modeling of oceanic detachments. Other seismically imaged detachments have similar dimensions and geometry, but are covered by a layer of small fault blocks. The detachment types differ in whether or not the fault locks up in the subsurface, probably controlled by the fault strength, the elastic thickness, and whether the exhumed footwall is partly covered by basalts. Toward the segment middle, decreasing mantle serpentinization, decreasing elastic thickness, and thicker median valley basalts all increase the likelihood that the fault locks up, and a new fault propagates upwards from the still active root zone, transferring a slice of the hanging wall to the footwall, to be rafted with the footwall out of the median valley. As a result an oceanic detachment fault, exhuming the footwall at a segment end to form an oceanic core complex, may disappear laterally beneath rafted blocks; detachment faulting may be more widespread at slow spreading ridges than interpreted from seafloor mapping. Copyright 2011 by the American Geophysical Union.}, keywords = {detachment fault}, issn = {15252027}, doi = {10.1029/2011GC003666}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79961244612\&partnerID=tZOtx3y1}, author = {Reston, T. J. and Ranero, C. R.} } @booklet {Sallares, title = {{Active faulting and slope failure in the Iberian margins: towards offshore geohazard mitigation}}, year = {2011}, publisher = {International Commission for the Scientific Exploration of the Mediterranean Sea}, abstract = {12 pages, 7 figures.}, url = {http://digital.csic.es/handle/10261/57350}, author = {Sallares, Valenti and Gr{\'a}cia, Eul{\`a}lia and Urgeles, Roger} } @article {Geersen2011, title = {{Active tectonics of the South Chilean marine fore arc (35{\textdegree}S-40{\textdegree}S)}}, journal = {Tectonics}, volume = {30}, number = {3}, year = {2011}, month = {jun}, pages = {n/a{\textendash}n/a}, abstract = {The South Chilean marine fore arc (35{\textdegree}S-40{\textdegree}S) is separated into four tectonic segments, Concepci{\'o}n North, Concepci{\'o}n South, Nahuelbuta, and Tolten (from north to south). These are each characterized by their individual tectonic geomorphology and reflect different ways of mechanical and kinematic interaction of the convergent Nazca and South American plates. Splay faults that cut through continental framework rock are seismically imaged in both Concepci{\'o}n segments and the Tolten Segment. Additionally, the Concepci{\'o}n South Segment exhibits prominent upper plate normal faults. Normal faults apparently relate to uplift caused by sediment underthrusting at depth. This has led to oversteepening and gravitational collapse of the marine fore arc. There is also evidence for sediment underthrusting and basal accretion to the overriding plate in the Tolten Segment. There, uplift of the continental slope has created a landward inclined seafloor over a latitudinal distance of 50 km. In the Nahuelbuta Segment transpressive upper plate faults, aligned oblique to the direction of plate motion, control the seafloor morphology. Based on a unique acoustic data set including >90\% of bathymetric coverage of the continental slope we are able to reveal an along-strike heterogeneity of a complexly deformed marine fore arc which had escaped attention in previous studies that only considered the structure along transects normal to the plate margin. Copyright 2011 by the American Geophysical Union.}, issn = {02787407}, doi = {10.1029/2010TC002777}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79958808106\&partnerID=tZOtx3y1}, author = {Geersen, Jacob and Behrmann, Jan H. and V{\"o}lker, David and Krastel, Sebastian and Ranero, Cesar R. and Diaz-Naveas, Juan and Weinrebe, Wilhelm} } @article {Kormann2011, title = {{Application of acoustic full waveform inversion to retrieve high-resolution temperature and salinity profiles from synthetic seismic data}}, journal = {Journal of Geophysical Research}, volume = {116}, number = {C11}, year = {2011}, month = {nov}, pages = {C11039}, abstract = {Recent works show that multichannel seismic (MCS) systems are able to provide detailed information on the oceans{\textquoteright} fine structure. The aim of this paper is to analyze whether 1-D full waveform inversion algorithms are suitable to recover the extremely weak acoustic impedance contrasts associated to the oceans{\textquoteright} fine structure, as well as their potential to image meso-scale objects such as meddies. We limited our analysis to synthetic, noise-free data, in order to identify some methodological issues related to this approach under idealistic conditions (e.g., 1-D wave propagation, noise-free data, known source wavelet). We first discuss the influence of the starting model in the context of the multi-scale strategy that we have implemented. Then we show that it is possible to retrieve not only sound speed but also salinity and temperature contrasts within reasonable bounds from the seismic data using Neural Network relationships trained with regional oceanographic data sets. Potentially, the vertical resolution of the obtained models, which depends on the maximum frequency inverted, is of the order of 5-10 m, whereas the root mean square error of the inverted properties is shown to be \~{}0.5 m/s for sound speed, 0.1C for temperature, and 0.06 for salinity. To conclude this study, we have inverted synthetic data simulated along an oceanographic transect acquired during the EU-funded Geophysical Oceanography (GO) project. The results demonstrate the applicability of the method for synthetic data, as well as its potential to define oceanographic features along 2-D transects at full ocean depth with excellent lateral resolution. Copyright 2011 by the American Geophysical Union.}, issn = {0148-0227}, doi = {10.1029/2011JC007216}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-82355181440\&partnerID=tZOtx3y1}, author = {Kormann, J. and Biescas, B. and Korta, N. and De La Puente, J. and Sallar{\`e}s, V.} } @article {Coiras2011, title = {{Automatic Segmentation of Multi-Beam Data for Predictive Mapping of Benthic Habitats on the Chella Seamount (North-Eastern Alboran Sea, Western Mediterranean)}}, journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing}, volume = {4}, number = {4}, year = {2011}, month = {dec}, pages = {809{\textendash}813}, abstract = {A reliable and objective classification method has been produced for the differentiation of benthic habitats in the seamount regions of the North-Eastern Alboran Sea. Acoustic backscatter and depth measurements from multi-beam data are automatically fused and then classified using video transects of known cold-water coral ecosystems as ground-truth. Results of the classification reveal the locations of potentially similar habitats in the region, and could be used as a base map for the planning of future scientific campaigns in the area. {\textcopyright} 2008 IEEE.}, keywords = {Acoustic imaging, automatic classification, benthic habitats, data fusion, marine geology}, issn = {1939-1404}, doi = {10.1109/JSTARS.2011.2123874}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-83655198294\&partnerID=tZOtx3y1}, author = {Coiras, Enrique and Lo Iacono, Claudio and Gr{\'a}cia, Eul{\`a}lia and Da{\~n}obeitia, Juanjo and Sanz, Jos{\'e} Luis} } @article {Santos2011, title = {{Compression and shear-wave velocities in discrete particle simulations of quartz granular packings: Improved Hertz-Mindlin contact model}}, journal = {GEOPHYSICS}, volume = {76}, number = {5}, year = {2011}, month = {sep}, pages = {E165{\textendash}E174}, abstract = {The Hertz-Mindlin (HM) contact model has been a cornerstone for the development of several effective medium theories (EMTs) aimed at describing the mesoscopic and macroscopic mechanical behavior of granular materials like unconsolidated sands. In addition, this model is at the core of most of the discrete particle method designs used to numerically solve for the responses of these heterogeneous materials to external perturbations, like acoustic and stress-strain experiments. However, this model has shown shortcomings in the description of the shear response characterization of granular materials, partly due to the non-affine motions experienced by the grains. We have developed a correction of the model based on a detailed calibration of our acoustic numerical results with previous empirical data. Using a microscopic approach to the grain-grain contact surfaces, the nature of the corrections found appear to be related to the shear resistant asperities and the smaller scale of the grain-grain contact areas compared to the total area assumed by the HM model. An improved HM model characterized by a tangential stiffness weakening is based on these surface corrections. Using this observation an enhanced EMT theory emerges based not only on the tangential stiffness modification but also on the velocity-pressure dependence obtained during the calibration of our numerical model. {\textcopyright} 2011 Society of Exploration Geophysicists.}, keywords = {3D, Compression wave (P-wave), Rock physics, Shear-wave (S-wave), Wave propagation}, issn = {0016-8033}, doi = {10.1190/geo2010-0376.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84857461284\&partnerID=tZOtx3y1}, author = {Santos, Carlos and Urdaneta, Vanessa and Garcia, Xavier and Medina, Ernesto} } @article {Dannowski2011, title = {{Crustal structure of the propagating TAMMAR ridge segment on the Mid-Atlantic Ridge, 21.5{\textdegree}N}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {12}, number = {7}, year = {2011}, month = {jul}, pages = {n/a{\textendash}n/a}, abstract = {Active ridge propagation frequently occurs along spreading ridges and profoundly affects ridge crest segmentation over time. The mechanisms controlling ridge propagation, however, are poorly understood. At the slow spreading Mid-Atlantic Ridge at 21.5{\textdegree}N a seismic refraction and wide-angle reflection profile surveyed the crustal structure along a segment controlled by rapid ridge propagation. Tomographic traveltime inversion of seismic data suggests that the crustal structure along the ridge axis is controlled by melt supply; thus, crust is thickest, 8 km, at the domed segment center and decreases in thickness toward both segment ends. However, thicker crust is formed in the direction of ridge propagation, suggesting that melt is preferentially transferred toward the propagating ridge tip. Further, while seismic layer 2 remains constant along axis, seismic layer 3 shows profound changes in thickness, governing variations in total crustal thickness. This feature supports mantle upwelling at the segment center. Thus, fluid basaltic melt is redistributed easily laterally, while more viscose gabbroic melt tends to crystallize and accrete nearer to the locus of melt supply. The onset of propagation seems to have coincided with the formation of thicker crust, suggesting that propagation initiation might be due to changes in the melt supply. After a rapid initiation a continuous process of propagation was established. The propagation rate seems to be controlled by the amount of magma that reaches the segment ends. The strength of upwelling may govern the evolution of ridge segments and hence ultimately controls the propagation length. Copyright 2011 by the American Geophysical Union.}, keywords = {Crustal structure, mid-ocean ridges, ridge propagation, seismic traveltime tomography}, issn = {15252027}, doi = {10.1029/2011GC003534}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79960696393\&partnerID=tZOtx3y1}, author = {Dannowski, A. and Grevemeyer, I. and Phipps Morgan, J. and Ranero, C. R. and Maia, M. and Klein, G.} } @article {Ribo2011, title = {{Dense shelf water cascades in the Cap de Creus and Palam{\'o}s submarine canyons during winters 2007 and 2008}}, journal = {Marine Geology}, volume = {284}, number = {1-4}, year = {2011}, month = {jun}, pages = {175{\textendash}188}, abstract = {The Cap de Creus and the Palam{\'o}s submarine canyon heads were instrumented during two consecutive winters to study their respective role in the dynamics of the sediment transport on the north-western Mediterranean Sea. Several events of dense shelf-water cascading (DSWC) were identified simultaneously at both canyons and compared between them. DSWC events were characterized by abrupt drops of temperature, increases of current speeds, and peaks of high suspended-sediment concentrations (SSC). Concentrations up to 170mg l -1 were recorded in both studied winters at the Cap de Creus Canyon coinciding with the first DSWC event of the winter concurrent with an eastern storm. Overall, the amount of sediment transported during the DSWC events was one order of magnitude greater at the Cap de Creus Canyon than at the Palam{\'o}s Canyon. Results from this study have identified for the first time the presence of DSWC events also in the Palam{\'o}s Canyon head, south of the Gulf of Lions (GoL), and corroborated previous findings that the Cap de Creus Canyon is the main pathway for DSWC and the associated sediment transport from the GoL down to the deeper regions of the north-western Mediterranean. {\textcopyright} 2011 Elsevier B.V.}, keywords = {Continental margin, Sediment transport, Submarine canyons, Western Mediterranean}, issn = {00253227}, doi = {10.1016/j.margeo.2011.04.001}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79957644806\&partnerID=tZOtx3y1}, author = {Rib{\'o}, M. and Puig, P. and Palanques, A. and Lo Iacono, C.} } @conference {Nagel2011, title = {{Discrete element hydraulic fracture modeling - Evaluating changes in natural fracture aperture and transmissivity}}, booktitle = {Society of Petroleum Engineers - Canadian Unconventional Resources Conference 2011, CURC 2011}, volume = {2}, year = {2011}, pages = {1350{\textendash}1363}, abstract = {Previous works have presented the results of successful simulations of fluid injection into naturally fractured shale using a Discrete Element Model (DEM). The simulations included coupled fluid flow-deformation analysis, failure type and extent calculations, as well as a series of parametric analyses. The parameters investigated included: 1) injection rate and its effect on the overall fracturing results, and 2) fluid viscosity, which had a significant influence on the ratio of tensile (mode 1) failure versus shear failure. With the huge growth in the stimulation of naturally fractured formations such as fractured shales, it is clear that the industry needs new hydraulic fracturing simulation tools beyond the limits imposed by pseudo3D fracturing models. DEMs, in which both matrix block behavior and fracture behavior are explicitly modeled, offer one option for the specific modeling of hydraulic fracture creation and growth in a naturally fractured formation without, for example, the assumption of bi-planar fracture growth. In this paper, we extend the previous works to quantify, for fractured shale gas plays, the effect of stress orientation, fluid viscosity, and rock mechanical properties in terms of changes in fracture aperture and transmissivity. Changes in fracture transmissivity directly correlate with improvements in well productivity - the primary goal of the stimulation. The results of the study provide a means to improve shale completions by understanding the effects of the DFN orientation relative to the stress field, fluid viscosity, and rock mechanical properties on changes in fracture aperture, fracture transmissivity, and formation effective permeability, which directly relate to well productivity. Copyright 2011, Society of Petroleum Engineers.}, isbn = {9781618394217}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84860594665\&partnerID=tZOtx3y1}, author = {Nagel, Neal and Damjanac, Branko and Garcia, Xavier and Sanchez-Nagel, Marisela} } @article {Evans2011, title = {{Electrical lithosphere beneath the Kaapvaal craton, southern Africa}}, journal = {Journal of Geophysical Research}, volume = {116}, number = {B4}, year = {2011}, month = {apr}, pages = {B04105}, abstract = {A regional-scale magnetotelluric (MT) experiment across the southern African Kaapvaal craton and surrounding terranes, called the Southern African Magnetotelluric Experiment (SAMTEX), has revealed complex structure in the lithospheric mantle. Large variations in maximum resistivity at depths to 200-250 km relate directly to age and tectonic provenance of surface structures. Within the central portions of the Kaapvaal craton are regions of resistive lithosphere about 230 km thick, in agreement with estimates from xenolith thermobarometry and seismic surface wave tomography, but thinner than inferred from seismic body wave tomography. The MT data are unable to discriminate between a completely dry or slightly "damp" (a few hundred parts per million of water) structure within the transitional region at the base of the lithosphere. However, the structure of the uppermost \~{}150 km of lithosphere is consistent with enhanced, but still low, conductivities reported for hydrous olivine and orthopyroxene at levels of water reported for Kaapvaal xenoliths. The electrical lithosphere around the Kimberley and Premier diamond mines is thinner than the maximum craton thickness found between Kimberley and Johannesburg/Pretoria. The mantle beneath the Bushveld Complex is highly conducting at depths around 60 km. Possible explanations for these high conductivities include graphite or sulphide and/or iron metals associated with the Bushveld magmatic event. We suggest that one of these conductive phases (most likely melt-related sulphides) could electrically connect iron-rich garnets in a garnet-rich eclogitic composition associated with a relict subduction slab. Copyright 2011 by the American Geophysical Union.}, issn = {0148-0227}, doi = {10.1029/2010JB007883}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79955426798\&partnerID=tZOtx3y1}, author = {Evans, Rob L. and Jones, Alan G. and Garcia, Xavier and Muller, Mark and Hamilton, Mark and Evans, Shane and Fourie, C. J. S. and Spratt, Jessica and Webb, Susan and Jelsma, Hielke and Hutchins, Dave} } @article {Miensopust2011, title = {{Lithospheric structures and Precambrian terrane boundaries in northeastern Botswana revealed through magnetotelluric profiling as part of the Southern African Magnetotelluric Experiment}}, journal = {Journal of Geophysical Research}, volume = {116}, number = {B2}, year = {2011}, month = {feb}, pages = {B02401}, abstract = {Within the framework of the Southern African Magnetotelluric Experiment a focused study was undertaken to gain improved knowledge of the lithospheric geometries and structures of the westerly extension of the Zimbabwe craton (ZIM) into Botswana, with the overarching aim of increasing our understanding of southern African tectonics. The area of interest is located in northeastern Botswana, where Kalahari sands cover most of the geological terranes and very little is known about lithospheric structures and thicknesses. Some of the regional-scale terrane boundary locations, defined based on potential field data, are not sufficiently accurate for local-scale studies. Investigation of the NNW-SSE orientated, 600 km long ZIM line profile crossing the Zimbabwe craton, Magondi mobile belt, and Ghanzi-Chobe belt showed that the Zimbabwe craton is characterized by thick (\~{}220 km) resistive lithosphere, consistent with geochemical and geothermal estimates from kimberlite samples of the nearby Orapa and Letlhakane pipes (\~{}175 km west of the profile). The lithospheric mantle of the Ghanzi-Chobe belt is resistive, but its lithosphere is only about 180 km thick. At crustal depths a northward dipping boundary between the Ghanzi-Chobe and the Magondi belts is identified, and two middle to lower crustal conductors are discovered in the Magondi belt. The crustal terrane boundary between the Magondi and Ghanzi-Chobe belts is found to be located further to the north, and the southwestern boundary of the Zimbabwe craton might be further to the west, than previously inferred from the regional potential field data. Copyright 2011 by the American Geophysical Union.}, issn = {0148-0227}, doi = {10.1029/2010JB007740}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79951472921\&partnerID=tZOtx3y1}, author = {Miensopust, M. P. and Jones, A. G. and Muller, M. R. and Garcia, X. and Evans, R. L.} } @article {Urgeles2011a, title = {{New constraints on the Messinian sealevel drawdown from 3D seismic data of the Ebro Margin, western Mediterranean}}, journal = {Basin Research}, volume = {23}, number = {2}, year = {2011}, month = {apr}, pages = {123{\textendash}145}, abstract = {We present new 3D seismic and well data from the Ebro Margin, NW Mediterranean Sea, to shed new light on the processes that formed the Messinian Erosion Surfaces (MES) of the Valencia Trough (Mediterranean Sea). We combine these data with backstripping techniques to provide a minimum estimate of the Messinian sea level fall in the EBRO Margin, as well as coupled isostasy and river incision and transport modeling to offer new constraints on the evolution of the adjacent subaerial Ebro Basin. Four major seismic units are identified on the Cenozoic Ebro Margin, based on the seismic data, including two major prograding megasequences that are separated by a major unconfirmity: the MES. The 3D seismic data provide an unprecedented view of the MES and display characteristic features of subaerial incision, including a drainage network with tributaries of at least five different orders, terraces and meandering rivers. The Messinian landscape presents a characteristic stepped-like profile that allows the margin to be subdivided in three different regions roughly parallel to the coastline. No major tectonic control exists on the boundaries between these regions. The boundary between the two most distal regions marks the location of a relatively stable base level, and this is used in backstripping analysis to estimate the magnitude of sea level drop associated with the Messinian Salinity Crisis on the Ebro Margin. The MES on the Ebro Margin is dominated by a major fluvial system, that we identify here as the Messinian Ebro River. The 3D seismic data, onshore geology and modeling results indicate that the Ebro River drained the Ebro Basin well in advance of the Messinian. {\textcopyright} 2010 The Authors. Basin Research {\textcopyright} 2010 Blackwell Publishing Ltd, European Association of Geoscientists \& Engineers and International Association of Sedimentologists.}, issn = {0950091X}, doi = {10.1111/j.1365-2117.2010.00477.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79952079451\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and Camerlenghi, Angelo and Garcia-Castellanos, Daniel and De Mol, Ben and Garc{\'e}s, Miquel and Verg{\'e}s, Jaume and Haslam, Ian and Hardman, Martin} } @article {Manchuel2011, title = {{New insights on the interseismic active deformation along the North Ecuadorian-South Colombian (NESC) margin}}, journal = {Tectonics}, volume = {30}, number = {4}, year = {2011}, month = {aug}, pages = {n/a{\textendash}n/a}, abstract = {The North Ecuadorian-South Colombian subduction zone was the site of the 1906 Mw 8.8 megathrust earthquake. This main shock was followed by three large events in 1942, 1958, and 1979 whose rupture zones were located within the 500 km long 1906 rupture area. A combined onshore and offshore temporary seismic network covering from the trench to the Andes was deployed during 3 months in the area of large earthquakes, in order to obtain a detailed knowledge of the seismic background activity. Resulting earthquakes location and mechanisms bring new insights on interseismic active deformation distribution in the three main tectonic units of the margin, namely, the Interplate Seismogenic Zone, the fore-arc region which is part of the North Andean Block and the downgoing oceanic Nazca plate. The interplate seismic activity presents along strike variations, suggesting that the seismicity and the associated stress buildup along the plate interface depend on the time elapsed since the last large earthquakes. According to our results, the updip and downdip limits of the seismogenic zone appear to be located at 12 and 30 km depth, respectively. Shallow to intermediate depth seismicity indicates a slab dip angle of ≈25{\textdegree}. North of the Carnegie Ridge, the Wadati-Benioff plane is defined beneath the fore arc down to ≈100 km depth. Facing the ridge, the Wadati-Benioff plane extends beneath the Andes, down to ≈140 km depth. This observation conflicts with the hypothesis of the presence of a flat slab at a depth of 100 km facing the ridge. In the overlying fore-arc region, the crustal seismicity occurs down to 40 km depth and is mainly concentrated in a roughly NW-SE 100 km wide stripe stretching from the coast, at about 1{\textdegree}N, to the Andes. The location of this active deformation stripe coincides with observed tectonic segmentation of the coastal domain as evidenced by the presence of an uplifting segment to the south and a subsiding segment to the north of the stripe. It also corresponds to a ≈30{\textdegree} change in the trend of the Andes, suggesting that the curvature of the volcanic arc might play an important role in the deformation of the fore-arc region. Copyright 2011 by the American Geophysical Union.}, issn = {02787407}, doi = {10.1029/2010TC002757}, url = {http://doi.wiley.com/10.1029/2010TC002757 http://www.scopus.com/inward/record.url?eid=2-s2.0-79960929640\&partnerID=tZOtx3y1}, author = {Manchuel, Kevin and R{\'e}gnier, Marc and B{\'e}thoux, Nicole and Font, Yvonne and Sallares, Valenti and D{\'\i}az, Jordi and Yepes, Hugo} } @article {Urgeles2011, title = {{A review of undulated sediment features on Mediterranean prodeltas: distinguishing sediment transport structures from sediment deformation}}, journal = {Marine Geophysical Research}, volume = {32}, number = {1-2}, year = {2011}, month = {apr}, pages = {49{\textendash}69}, abstract = {Most Mediterranean prodeltas show undulated sediment features on the foresets of their Holocene wedges. These features have been described all along the Mediterranean for the last 30 years and interpreted as either soft sediment deformation and incipient landsliding, and more recently, as sediment transport structures. We perform a review and detailed analysis of these undulated sediment features using ultrahigh-resolution seismic and bathymetric data as well as geotechnical information and hydrodynamic time series and hydrographic transects. In this study we show that the characteristics of the sediment undulations (configuration of the reflections down section and between adjacent undulations and overall morphologic characteristics) are incompatible with a genesis by sediment deformation alone and do not show evidence of sediment deformation in most cases. Various processes in the benthic boundary layer can be invoked to explain the variety of features observed in the numerous areas displaying sediment undulations. {\textcopyright} 2011 Springer Science+Business Media B.V.}, keywords = {Hyperpycnal flows, Internal waves, Prodeltas, Sediment waves, slope failure, Undulated sediments}, issn = {0025-3235}, doi = {10.1007/s11001-011-9125-1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79961209935\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and Cattaneo, Antonio and Puig, Pere and Liquete, Camino and De Mol, Ben and Amblas, David and Sultan, Nabil and Trincardi, Fabio} } @article {Pedrosa2011, title = {{Seabed morphology and shallow sedimentary structure of the Storfjorden and Kveithola trough-mouth fans (North West Barents Sea)}}, journal = {Marine Geology}, volume = {286}, number = {1-4}, year = {2011}, month = {aug}, pages = {65{\textendash}81}, abstract = {This study aims to present an overview of the seafloor morphology and shallow sedimentary structure of the Storfjorden and Kveithola Trough Mouth Fans (TMFs) on the northwestern Barents Sea continental margin. Data have been compiled from two International Polar Year (IPY) cruises (SVAIS, of the BIO Hesp{\'e}rides and EGLACOM of the R/V OGS-Explora) that yielded 15,340km2 of multi-beam bathymetry and 9500km of sub-bottom seismic profiles. In this area, the continental shelf edge defines three wide and subdued sedimentary lobes forming Storfjorden TMF, one single lobe on Kveithola TMF, and three inter-TMF areas on the continental slope. The two northernmost lobes of Storfjorden TMF (Lobes I and II) are composed by thick (up to 50m) sequences of glacially derived debris flow deposits interbedded with thin a few metres de-glacial and interglacial deposits. A network of upper slope gullies incises these debris flow deposits as a consequence of subglacial meltwater release at or near the shelf break. Gullies evolve into channels whose morphologic evidence disappears midslope, leaving place to a subdued chevron-like morphological pattern inherited by the preceeding glacial maximum debris flow deposits. A drastic change occurs on the continental slope of Storfjorden TMF Lobe III and Kveithola TMF, where are several translational submarine landslides mostly originated in the upper slope, the majority of which detach at the contact between Middle Weishelian glacigenic debris flows and the overlying acoustically laminated plumites. Dendritic canyon systems only develop in inter-TMF areas. The data suggest that TMF continental slope progradation depends on short-lived episodes of extreme sedimentation during glacial maxima and during the early deglaciation phase, and that an important controlling factor is the mechanism of ice stream retreat from the continental shelf edge. We suggest that the two northern Storfjorden sub-ice streams were composed of thicker and perhaps faster ice progressively draining a distal and larger ice source mainly located on Svalbard. Conversely, the southernmost Storfjorden sub-ice stream and the Kveithola ice stream were fed by a local, smaller marine-based ice dome grounded on Spitsbergenbanken. The ice dome persisted after the LGM, maintaining a local ice drainage system close to the shelf edge whose sedimentary evidence can be found on the continental slope of the southern lobe of Storfjorden TMF and Kveithola TMF. The high degree of lateral variability in the style of sedimentation on TMF slopes suggests that ice stream dynamics may vary considerably within the same glacial trough, and that such variability affects the long-term development of the architecture of TMFs. {\textcopyright} 2011 Elsevier B.V.}, keywords = {Barents Sea, Deglaciation, Glacial maximum, Paleo-ice streams, Storfjorden, Svalbard}, issn = {00253227}, doi = {10.1016/j.margeo.2011.05.009}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80051568915\&partnerID=tZOtx3y1}, author = {Pedrosa, M.T. and Camerlenghi, A. and De Mol, B. and Urgeles, R. and Rebesco, M. and Lucchi, R.G.} } @article {Chiocci2011, title = {{Seafloor mapping for geohazard assessment: state of the art}}, journal = {Marine Geophysical Research}, volume = {32}, number = {1-2}, year = {2011}, month = {may}, pages = {1{\textendash}11}, abstract = {During the last two decades, increasing use of full-coverage sonic mapping of the seafloor has made us more aware of the large and different number of seafloor processes and events bearing significant geohazard potential. This awareness combines with the increasing use of the seafloor for infrastructure and with the high density of population and settlement on the coast. Seafloor mapping is the first step in making a census of the geohazard-bearing features present in a given offshore area. It often provides the only tool for a comprehensive, although non-specific, seafloor geohazard assessment over large areas that are scarcely groundtruthed by acoustic prospection and seafloor sampling. However, the characterization of geohazard features on a morphological basis alone is limited, and more detailed investigations are needed to define the character and state of activity of potentially hazardous features. Such investigations include the use of deep-tow or autonomous platforms designed to acquire high-resolution data at depth as well as in situ measurements, both being very expensive activities not applicable over large areas. Thus seafloor mapping is often not only the first and the main but also the only tool for a comprehensive seafloor geohazard assessment. This special issue represents an example of the diversity of approaches to seafloor geohazard assessment and summarizes the present state of this discipline. Both the diverse technologies applied and the specific aims of offshore geohazard assessment brought different communities to deal with the study of seafloor processes and events from remarkably distinct viewpoints. We identified three end members in offshore geohazard assessment: (1) geohazard assessment "sensu stricto", (2) "engineering" geohazard assessment, (3) "non-specific" geohazard assessment. These are being conducted by industry, academia and public agencies in charge of civil protection and land-use planning and management. Understanding the needs and geohazard perception of the different groups is a necessary step for a profitable collaboration in such an interesting and rapidly developing field of marine geology. {\textcopyright} 2011 Springer Science+Business Media B.V.}, keywords = {Geological risks, Multibeam bathymetry, Natural hazards, Seafloor morphology, Submarine landslides}, issn = {0025-3235}, doi = {10.1007/s11001-011-9139-8}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79957484646\&partnerID=tZOtx3y1}, author = {Chiocci, Francesco L. and Cattaneo, Antonio and Urgeles, Roger} } @article {Sallares2011, title = {{Seismic evidence for the presence of Jurassic oceanic crust in the central Gulf of Cadiz (SW Iberian margin)}}, journal = {Earth and Planetary Science Letters}, volume = {311}, number = {1-2}, year = {2011}, month = {nov}, pages = {112{\textendash}123}, abstract = {We investigate the crustal structure of the SW Iberian margin along a 340. km-long refraction and wide-angle reflection seismic profile crossing from the central Gulf of Cadiz to the Variscan continental margin in the Algarve, Southern Portugal. The seismic velocity and crustal geometry model obtained by joint refraction and reflection travel-time inversion reveal three distinct crustal domains: the 28-30. km-thick Variscan crust in the north, a 60. km-wide transition zone offshore, where the crust abruptly thins \~{}. 20. km, and finally a \~{}. 7. km-thick and \~{}. 150. km-wide crustal section that appears to be oceanic in nature. The oceanic crust is overlain by a 1-3. km-thick section of Mesozoic to Eocene sediments, with an additional 3-4. km of low-velocity, unconsolidated sediments on top belonging to the Miocene age, Gulf of Cadiz imbricated wedge. The sharp transition between continental and oceanic crust is best explained by an initial rifting setting as a transform margin during the Early Jurassic that followed the continental break-up in the Central Atlantic. The narrow oceanic basin would have formed during an oblique rifting and seafloor spreading episode between Iberia and Africa that started shortly thereafter (Bajocian) and lasted up to the initiation of oceanic spreading in the North Atlantic at the Tithonian (late Jurassic-earliest Cretaceous). The velocity model displays four wide, prominent, south-dipping low-velocity anomalies, which seem to be related with the presence of crustal-scale faults previously identified in the area, some of which could well be extensional faults generated during this rifting episode. We propose that this oceanic plate segment is the last remnant of an oceanic corridor that once connected the Alpine-Tethys with the Atlantic ocean, so it is, in turn, one of the oldest oceanic crustal fragments currently preserved on Earth. The presence of oceanic crust in the central Gulf of Cadiz is consistent with geodynamic models suggesting the existence of a narrow, westward retreating oceanic slab beneath the Gibraltar arc-Alboran basin system. {\textcopyright} 2011 Elsevier B.V.}, keywords = {Geodynamic evolution, Jurassic oceanic crust, Refraction and reflection travel-time tomography, SW Iberian margin, Uncertainty analysis, wide-angle seismics}, issn = {0012821X}, doi = {10.1016/j.epsl.2011.09.003}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-81155155560\&partnerID=tZOtx3y1}, author = {Sallares, Valenti and Gailler, Audrey and Gutscher, Marc-Andr{\'e} and Graindorge, David and Bartolom{\'e}, Rafael and Gr{\'a}cia, Eul{\`a}lia and D{\'\i}az, Jordi and Da{\~n}obeitia, Juan Jos{\'e} and Zitellini, Nevio} } @article {LoIacono2011, title = {{Submarine canyon morphologies in the Gulf of Palermo (Southern Tyrrhenian Sea) and possible implications for geo-hazard}}, journal = {Marine Geophysical Research}, volume = {32}, number = {1-2}, year = {2011}, month = {mar}, pages = {127{\textendash}138}, abstract = {The continental shelf and the upper slope of the Gulf of Palermo (Southern Tyrrhenian Sea) in the depth interval ranging from 50 to 1,500 m were mapped for the first time with Multi Beam echosounder and high resolution seismic. Seven submarine canyons are confined to the upper slope or indent the shelf-edge and enter the Palermo intraslope basin at a depth of around 1,300 m. The canyons evolved through concurrent top-down turbiditic processes and bottom-up retrogressive mass failures. Most of the mass failure features of the area are related to canyon-shaping processes and only few of them are not confined to the upper slope. In general, these features probably do not represent a significant tsunami hazard along the coast. The geological element that controls the evolution of the canyons and induces sediment instability corresponds to the steep slope gradient, especially in the western sector of the Gulf, where the steepest canyons are located. The structural features mapped in the Palermo offshore contributed to the regulation of mass failure processes in the area, with direct faults and antiform structures coinciding with some of the canyon heads. Furthermore, the occurrence of pockmarks and highs that probably consist of authigenic carbonates above faulted and folded strata suggests a local relationship between structural control, fluid escape processes and mass failure. This paper presents a valuable high-resolution morphologic dataset of the Gulf of Palermo, which constitutes a reliable base for evaluating the geo-hazard potential related to slope failure in the area. {\textcopyright} 2011 Springer Science+Business Media B.V.}, keywords = {Geo-hazard, Mass failure processes, Southern Mediterranean, Submarine canyons, Swath mapping}, issn = {0025-3235}, doi = {10.1007/s11001-011-9118-0}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79961169577\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Sulli, Attilio and Agate, Mauro and Lo Presti, Valeria and Pepe, Fabrizio and Catalano, Raimondo} } @booklet {Sueng-Won, title = {{Submarine Landslides: Science, Technology and Challenges}}, year = {2011}, publisher = {Taehan t{\textquoteright}omok hakhoe}, abstract = {8 pages, 11 figures.}, url = {http://digital.csic.es/handle/10261/57343}, author = {Sueng-Won, Jeong and Locat, Jacques and Leroueil, Serge and Urgeles, Roger} } @article {Harders2011, title = {{Submarine slope failures along the convergent continental margin of the Middle America Trench}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {12}, number = {6}, year = {2011}, month = {jun}, pages = {n/a{\textendash}n/a}, abstract = {We present the first comprehensive study of mass wasting processes in the continental slope of a convergent margin of a subduction zone where tectonic processes are dominated by subduction erosion. We have used multibeam bathymetry along \~{}1300 km of the Middle America Trench of the Central America Subduction Zone and deep-towed side-scan sonar data. We found abundant evidence of large-scale slope failures that were mostly previously unmapped. The features are classified into a variety of slope failure types, creating an inventory of 147 slope failure structures. Their type distribution and abundance define a segmentation of the continental slope in six sectors. The segmentation in slope stability processes does not appear to be related to slope preconditioning due to changes in physical properties of sediment, presence/absence of gas hydrates, or apparent changes in the hydrogeological system. The segmentation appears to be better explained by changes in slope preconditioning due to variations in tectonic processes. The region is an optimal setting to study how tectonic processes related to variations in intensity of subduction erosion and changes in relief of the underthrusting plate affect mass wasting processes of the continental slope. The largest slope failures occur offshore Costa Rica. There, subducting ridges and seamounts produce failures with up to hundreds of meters high headwalls, with detachment planes that penetrate deep into the continental margin, in some cases reaching the plate boundary. Offshore northern Costa Rica a smooth oceanic seafloor underthrusts the least disturbed continental slope. Offshore Nicaragua, the ocean plate is ornamented with smaller seamounts and horst and graben topography of variable intensity. Here mass wasting structures are numerous and comparatively smaller, but when combined, they affect a large part of the margin segment. Farther north, offshore El Salvador and Guatemala the downgoing plate has no large seamounts but well-defined horst and graben topography. Off El Salvador slope failure is least developed and mainly occurs in the uppermost continental slope at canyon walls. Off Guatemala mass wasting is abundant and possibly related to normal faulting across the slope. Collapse in the wake of subducting ocean plate topography is a likely failure trigger of slumps. Rapid oversteepening above subducting relief may trigger translational slides in the middle Nicaraguan upper Costa Rican slope. Earthquake shaking may be a trigger, but we interpret that slope failure rate is lower than recurrence time of large earthquakes in the region. Generally, our analysis indicates that the importance of mass wasting processes in the evolution of margins dominated by subduction erosion and its role in sediment dynamics may have been previously underestimated. Copyright 2011 by the American Geophysical Union.}, keywords = {Convergent margin, landslides, slope failure, Subduction erosion, submarine mass wasting, tectonics}, issn = {15252027}, doi = {10.1029/2010GC003401}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79959701829\&partnerID=tZOtx3y1}, author = {Harders, Rieka and Ranero, Cesar R. and Weinrebe, Wilhelm and Behrmann, Jan H.} } @article {Moore2011, title = {{Threshold of borehole failure: Breaking in before breaking out, Mississippi fan, Gulf of Mexico}}, journal = {Geosphere}, volume = {7}, number = {3}, year = {2011}, pages = {684{\textendash}693}, abstract = {Resistivity images from Integrated Ocean Drilling Program (IODP) Site U1322 on the Mississippi fan (Gulf of Mexico) show borehole failure as (1) low-resistivity bands interpreted as breakouts and (2) high-resistivity bands. Both features occur as opposing pairs on opposite sides of the borehole, and have similar azimuthal orientations and widths. Failures occur at depths of 90-216 m in sediments very rich in expansive (smectite-illite) clays of 40\%-50\% porosity that are younger than 65 ka. The low-resistivity breakouts resemble similar features in other IODP boreholes from southwest Japan and offshore Oregon. The high-resistivity features are unknown in other boreholes. Estimates of stress magnitudes based on the overburden stress and the extensional tectonic environment in the Gulf of Mexico predict that the borehole was at failure. Experiments were conducted on cores with lithologies equivalent to those of the borehole failure localities from IODP Site U1322 and adjacent Site U1324. These experiments suggest an elastic-plastic deformation with strains of 10\%-15\% before reaching a plastic yielding. In the experiments, strain softening during plastic deformation ranges from 0\% to 20\%. Physically the experimental samples show a combination of lateral bulging and discrete conjugate shears. These experiments suggest that the resistive areas in the borehole are an initial state of bulging, or extrusion, into the borehole. We call these extrusive failures "breakins" to distinguish them from traditional breakouts. Extrusion into borehole decreases the amount of conductive borehole fluid between the bulging sediment and the resistivity tool, increasing the resistivity signal. The high residual strength of the sediment prevents disaggregation and spalling. Where spalling has developed, breakouts occur. This analysis is the first documentation of this incipient stage of borehole failure. {\textcopyright} 2011 Geological Society of America.}, issn = {1553-040}, doi = {10.1130/GES00613.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80054764068\&partnerID=tZOtx3y1}, author = {Moore, J. Casey and Roger Urgeles, R. and Conin, Marianne and Flemings, Peter B. and Iturrino, Gerardo J.} } @article {Amblas2011, title = {{Transient erosion in the Valencia Trough turbidite systems, NW Mediterranean Basin}}, journal = {Geomorphology}, volume = {130}, number = {3-4}, year = {2011}, month = {jul}, pages = {173{\textendash}184}, abstract = {Submarine canyons can efficiently drain sediments from continental margins just as river systems do in subaerial catchments. Like in river systems, submarine canyons are often arranged as complex drainage networks that evolve from patterns of erosion and deposition. In the present paper we use a morphometric analysis of submarine canyon-channel long-profiles to study the recent sedimentary history of the Valencia Trough turbidite system (VTTS) in the NW Mediterranean Sea. The VTTS is unique in that it drains sediment from margins with contrasting morphologies through a single "trunk" conduit, the Valencia Channel. The Valencia Channel has been active since the late Miocene, evolving in response to Plio-Quaternary episodes of erosion and deposition. The integrated analysis of long-profiles obtained from high-resolution bathymetric data across the entire turbidite system shows evidence for transient canyon incision in the form of knickpoints and hanging tributaries. Multiple factors appear to have triggered these periods of incision. These include a large debris flow at 11,500. yr. BP that disrupted the upper reaches of the VTTS and glacio-eustatic lowstands that forced shifting of sediment input to the VTTS. Based on these inferences, long-term time-averaged incision rates for the Valencia Channel have been estimated. The evidence we present strongly suggests that Foix Canyon has played a key role in the drainage dynamics of the VTTS in the past.This study builds conceptually on a recent modeling study that provides a morphodynamic explanation for the long-term evolution of submarine canyon thalweg profiles. The procedure and results from this work are of potential application to other submarine sediment drainage systems, past and present, including those containing mid-ocean type valleys like the Valencia Channel. {\textcopyright} 2011 Elsevier B.V.}, keywords = {Knickpoints, Long-profiles, Submarine canyons, Transient erosion, Turbidity currents}, issn = {0169555X}, doi = {10.1016/j.geomorph.2011.03.013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79956155543\&partnerID=tZOtx3y1}, author = {Amblas, David and Gerber, Thomas P. and Canals, Miquel and Pratson, Lincoln F. and Urgeles, Roger and Lastras, Galderic and Calafat, Antoni M.} } @article {Garcia2011, title = {{Tricyclic Antidepressants-loaded Biodegradable PLGA Nanoparticles: In Vitro Characterization and In Vivo Analgesic and Anti-Allodynic Effect}}, journal = {Current Nanoscience}, volume = {7}, number = {3}, year = {2011}, month = {jun}, pages = {345{\textendash}353}, abstract = {Tricyclic antidepressants (TCAs) have potent local pain blockade properties that could be of interest in relieving chronic pain states as neuropathic pain. The aim of this work was to reach a persistent control of nociceptive and neuropathic pain by means of an in- jectable controlled release system using lower than usual doses of TCAs. To address this issue, amitriptyline, doxepin and imipramine were encapsulated with poly (lactic-co-glycolic) acid (PLGA) as polymer. Nanoparticles were characterized. The in vitro drug release profile and mechanism was evaluated, and the in vivo analgesic and anti-allodynic activity in front of heat-induced nociceptive pain and sciatic nerve chronic constriction injury, respectively, was tested. The mean{\textpm}SD particle size and drug loadings (\%) of the nanoparticles obtained were 420{\textpm}13, 480{\textpm}73 and 373{\textpm}25nm, and 40.46{\textpm}4.11, 31.09{\textpm}3.02 and 32.20{\textpm}3.20\% for amitriptyline, doxepin and imi- pramine, respectively. According to the Korsmeyer-Peppas model, the release mechanism of doxepin was diffusion controlled, while a combination of Fickian diffusion and polymer relaxation/erosion of the PLGA matrix was involved for amitriptyline and imipramine. Af- ter local infiltration of nanoparticles in rats, the antinociceptive and anti-allodynic activity of the encapsulated drugs were long-lasting and higher than that observed from the solutions. Amitriptyline elicited the lower analgesic effect. Doxepin showed the most outstanding results and its encapsulation led to a 62\% and 229\% increase in antinociceptive and anti-allodynic activity, respectively. So, this drug could be considered as a therapeutical alternative in pain relieving treatments.{\textcopyright} 2011 Bentham Science Publishers Ltd.}, keywords = {Anti-allodynia, Antinociception, In vitro release, Korsmeyer-peppas, Plga nanoparticles, Tricyclic antidepressants}, issn = {15734137}, doi = {10.2174/157341311795542336}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79956288549\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Escribano, Elvira and Colom, Helena and Domenech, Josep and Queralt, Josep} } @article {Garcia2011a, title = {{A two-phase adaptive finite element method for solid-fluid coupling in complex geometries}}, journal = {International Journal for Numerical Methods in Fluids}, volume = {66}, number = {1}, year = {2011}, month = {may}, pages = {82{\textendash}96}, abstract = {In this paper we present a method to solve the Navier-Stokes equations in complex geometries, such as porous sands, using a finite-element solver but without the complexity of meshing the porous space. The method is based on treating the solid boundaries as a second fluid and solving a set of equations similar to those used for multi-fluid flow. When combined with anisotropic mesh adaptivity, it is possible to resolve complex geometries starting with an arbitrary coarse mesh. The approach is validated by comparing simulation results with available data in three test cases. In the first we simulate the flow past a cylinder. The second test case compares the pressure drop in flow through random packs of spheres with the Ergun equation. In the last case simulation results are compared with experimental data on the flow past a simplified vehicle model (Ahmed body) at high Reynolds number using large-eddy simulation (LES). Results are in good agreement with all three reference models. {\textcopyright} 2010 John Wiley \& Sons, Ltd..}, keywords = {Anisotropic mesh adaptivity, Ergun equation, Flow past a cylinder, Flow past sphere packs, Flow past the Ahmed body, Two-fluid approach}, issn = {02712091}, doi = {10.1002/fld.2249}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79953156921\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Pavlidis, Dimitrios and Gorman, Gerard J. and Gomes, Jefferson L. M. A. and Piggott, Matthew D. and Aristodemou, Elsa and Mindel, Julian and Latham, John-Paul and Pain, Christopher C. and ApSimon, Helen} } @article {Garcia2010a, title = {{Analgesic and antiallodynic effects of antidepressants after infiltration into the rat.}}, journal = {Pharmacology}, volume = {86}, number = {4}, year = {2010}, month = {jan}, pages = {216{\textendash}23}, abstract = {Tricyclic antidepressants (TCA) have potent local anesthetic properties and may produce a long-lasting pain blockade that could be of interest in relieving chronic pain states such as neuropathic pain, but there are only few data comparing their dose-response curves of analgesic activity under the same experimental conditions. This study examines the time course of pain-relieving properties of 7 TCA in heat-induced paw withdrawal after subcutaneous administration. Mixed inhibitors of norepinephrine and serotonin uptake (amitriptyline, nortriptyline, imipramine, desipramine, doxepin) and selective inhibitors of serotonin uptake (fluoxetine and fluvoxamine) were assayed. The TCA with the longest analgesic activity were selected to test its antiallodynic effect in the neuropathic pain model of chronic sciatic nerve constriction injury. Bupivacaine was used as a reference drug in both experiments. A dose versus time of maximal analgesic effect curve was constructed for each drug. The longest analgesic effect was obtained for doxepin and imipramine. Although low doses of amitriptyline showed the same activity than doxepin, higher doses failed to reach the same effect. Selective inhibitors of serotonin showed no action at all doses tested. In the chronic sciatic nerve constriction injury model, doxepin and, to a smaller degree, amitriptyline and imipramine protected from allodynia; bupivacaine was ineffective. The antiallodynic effect always lasted less long than the analgesic effect. These observations provide support for the potential use of TCA as durable analgesics. Doxepin overall showed the most outstanding results in pain relief.}, keywords = {Adrenergic Uptake Inhibitors, Adrenergic Uptake Inhibitors: administration \& dos, Adrenergic Uptake Inhibitors: pharmacology, Analgesics, Analgesics: administration \& dosage, Analgesics: pharmacology, Anesthetics, Animal, Animals, Antidepressive Agents, Bupivacaine, Bupivacaine: pharmacology, Disease Models, Dose-Response Relationship, Drug, Hyperalgesia, Hyperalgesia: drug therapy, Local, Local: pharmacology, Male, Pain, Pain: drug therapy, Rats, Sciatic Neuropathy, Sciatic Neuropathy: drug therapy, Serotonin Uptake Inhibitors, Serotonin Uptake Inhibitors: administration \& dosa, Serotonin Uptake Inhibitors: pharmacology, Sprague-Dawley, Time Factors, Tricyclic, Tricyclic: administration \&, Tricyclic: pharmacology}, issn = {1423-0313}, doi = {10.1159/000319747}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956380582\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and del Valle, Jaume and Escribano, Elvira and Domenech, Josep and Queralt, Josep} } @conference {Melendez2010, title = {{Appraisal of joint refraction and reflection travel-time tomography in the context of weathering correction}}, booktitle = {72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010}, volume = {6}, year = {2010}, pages = {4692{\textendash}4696}, abstract = {We propose an application of joint refraction and reflection travel-time tomography to determine both velocity and thickness of the weathering layer to be used in statics correction. This low velocity layer affects the quality of seismic images. The innovative aspect of our approach is the use of refracted and reflected phases. This remarkably reduces the trade-off between depth and velocity. First arrivals can be automatically picked and the reflection at the layer bottom can be easily identified because of the high impedance contrast with the basement. Synthetic data are generated for a reference model with an acquisition geometry simulating production experiments. The reference model is modified by adding a velocity perturbation and displacing the reflector to create the initial model for the inversion. Travel-time residuals decrease from \~{}1 s to \~{}0.1 s and the reflector is recovered to within {\textpm}2 m. A Monte Carlo analysis is performed to calculate the mean deviation and its reduction as a measure of the model parameters uncertainty. The improvement (10-50\%) is more significant in areas covered by reflections and refractions, while the reflector is again limited to a \~{}2 m range. We are testing this application with real data. {\textcopyright} 2010, European Association of Geoscientists and Engineers.}, isbn = {9781617386671}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78249271372\&partnerID=tZOtx3y1}, author = {Mel{\'e}ndez, A. and De La Puente, J. and Sallar{\`e}s, V. and Ranero, C. R.} } @booklet {Gracia2010a, title = {{Characterizing active faults and associated mass transport deposits in the South Iberian Margin (Alboran Sea and Gulf of Cadiz): On-fault and off-fault paleoseismic evidence}}, journal = {Res{\'u}menes de la 1{\textordfeminine} Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a}, year = {2010}, month = {sep}, pages = {163{\textendash}166}, abstract = {Gr{\`a}cia, Eul{\`a}lia ... et al.{\textendash} Primera Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a. Sig{\"u}enza (Guadalajara, Espa{\~n}a) 27, 28 y 29 de Octubre de 2010.{\textendash} 4 pages, 1 figure}, isbn = {isbn: 978-84-693-6088-0}, url = {http://digital.csic.es/handle/10261/82464}, author = {Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, Rafael and Lo Iacono, Claudio and Moreno, Ximena and Martinez-Loriente, S. and Perea, H and Masana, E and Pall{\`a}s, R and S., Diez and Da{\~n}obeitia, Juan Jos{\'e} and Terrinha, P and Zitellini, N} } @article {Nemser, title = {{Compilation of parameterized seismogenic sources in Iberia for the SHARE European-scale seismic source model.}}, year = {2010}, pages = {201{\textendash}204}, keywords = {Database, Fault, Seismogenic, SHARE}, isbn = {978-84-693-6088-0}, url = {https://dspace.uevora.pt/rdpc/handle/10174/6247}, author = {Nemser, E.S. and Garc{\'\i}a-Mayordomo, J. and Cabral, J. and Fonseca, J. and Mart{\'\i}nez-D{\'\i}az, J.J. and Alfaro Garc{\'\i}a, P. and {\`A}lvarez G{\'o}mez, J.A. and Atakan, K. and Aza{\~n}{\'o}n Hern{\'a}ndez, J.M. and Basili, R. and Besana-Ostman, G.M. and Bezzeghoud, M. and Borges, J.F. and Brum da Silveira, A. and Carlos Lopes, F. and Carvalho, J. and Dias, R.P. and Figueiredo, P.M. and Garc{\'\i}a Fern{\'a}ndez, M. and Giner Robles, J. and Gonzalez, A. and Gr{\`a}cia, E. and Gutierrez, F. and Insua Ar{\'e}valo, J.M. and Jim{\'e}nez, M.J. and Jim{\'e}nez-D{\'\i}az, A. and Lafuente Tom{\'a}s, P. and Lucha, P. and Madeira, J. and Martin Gonz{\'a}lez, F. and Masana, E. and Matias, L. and Moreno, X. and Ortu{\~n}o, M. and Perea, H. and P{\'e}rez L{\'o}pez, R. and Rodr{\'\i}guez Pascua, M.A. and Ruano, P. and Santanach, P. and Sanz de Galdeano, C. and Silva Barroso, P. and Silva, S. and Sim{\'o}n, J.L. and Terrinha, P. and Vilanova, S. and Villamor, P. and Wong, J.} } @conference {Camerlenghi2010, title = {{A database on submarine landslides of the mediterranean sea}}, booktitle = {Submarine Mass Movements and Their Consequences - 4th International Symposium}, year = {2010}, pages = {503{\textendash}513}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, abstract = {Submarine landslides are ubiquitous along the continental margins of the Mediterranean basin and occur on tectonically-dominated margins as well as on passive margins and volcanic island flanks. Tectonically quiet zones seem to have the highest density of known events. Most landslides occur as long run-out distance debris flows, but slumps and deep-seated failures are also relatively common. In abyssal plains the distal product of massive failures is recorded as large megatur-bidites, while on volcanic islands the dominant failure type is flank-collapse with development of debris avalanches. Submarine landslides, excluding megaturbidites, appear to occur in all water depths between the coastline and about 2000 m. Most landslides occupy areas ranging from a few to about 600 km2 and volumes up to 220 km3. Abyssal plain megaturbidites can attain 60, 000 km2 and 1, 000 km3. The landslides headwall height are clustered around two modes: 0 to 40 m for relatively small landslides and 160 to 200 m for the largest ones. Most recorded submarine landslides are relatively young in age and several events appear to group near the Pleistocene to Holocene transition. {\textcopyright} Springer Science + Business Media B.V. 2010.}, keywords = {Geohazard, Holocene, Mass wasting, Mediterranean, Megaturbidite, Pleistocene, Submarine landslide}, isbn = {9789048130702}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903488503\&partnerID=tZOtx3y1}, author = {Camerlenghi, A. and Urgeles, R. and Fantoni, L.} } @article {Geissler2010, title = {{Focal mechanisms for sub-crustal earthquakes in the Gulf of Cadiz from a dense OBS deployment}}, journal = {Geophysical Research Letters}, volume = {37}, number = {18}, year = {2010}, month = {sep}, pages = {n/a{\textendash}n/a}, abstract = {An eleven-month deployment of 25 ocean bottom seismometers provides an unprecedented opportunity to study low-magnitude local earthquakes in the complex transpressive plate boundary setting of the Gulf of Cadiz, known for the 1755 Lisbon earthquake and tsunami. 36 relocated earthquakes (ML 2.2 to 4.8) concentrate at 40-60 km depth, near the base of the seismogenic layer in \~{}140 Ma old oceanic mantle lithosphere, and roughly align along two perpendicular, NNE-SSW and WNW-ESE striking structures. First motion focal mechanisms indicate compressive stress for the cluster close to the northern Horseshoe fault termination which trends perpendicular to plate convergence. Focal mechanisms for the second cluster near the southern termination of the Horseshoe fault indicate a strike-slip regime, providing evidence for present-day activity of a dextral shear zone proposed to represent the Eurasia-Africa plate contact. We hypothesize that regional tectonics is characterized by slip partitioning. {\textcopyright} 2010 by the American Geophysical Union.}, issn = {00948276}, doi = {10.1029/2010GL044289}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957722745\&partnerID=tZOtx3y1}, author = {Geissler, W. H. and Matias, L. and Stich, D. and Carrilho, F. and Jokat, W. and Monna, S. and IbenBrahim, A. and Mancilla, F. and Gutscher, M.-A. and Sallar{\`e}s, V. and Zitellini, N.} } @conference {Urgeles2010, title = {{History of pore pressure build up and slope instability in mud-dominated sediments of Ursa Basin, Gulf of Mexico continental slope}}, booktitle = {Submarine Mass Movements and Their Consequences - 4th International Symposium}, year = {2010}, pages = {179{\textendash}190}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, abstract = {The Ursa Basin, at \~{}1, 000 m depth on the Gulf of Mexico continental slope, contains numerous Mass Transport Deposits (MTDs) of Pleistocene to Holocene age. IODP Expedition 308 drilled three sites through several of these MTDs and encompassing sediments. Logs, sedimentological and geotechnical data were collected at these sites and are used in this study for input to basin numerical models. The objective of this investigation was to understand how sedimentation history, margin architecture and sediment properties couple to control pore pressure build-up and slope instability at Ursa. Measurements of porosity and stress state indicate that fluid overpressure is similar at the different sites (in the range of 0.5-0.7) despite elevated differences in sedimentation rates. Modeling results indicate that this results from pore pressure being transferred from regions of higher to lower overburden along an underlying more permeable unit: the Blue Unit. Overpressure started to develop at \~{}53 ka, which induced a significant decrease in FoS from 45ka, especially where overburden is lower. {\textcopyright} Springer Science + Business Media B.V. 2010.}, keywords = {Basin modeling, Pore pressure, Scientific drilling, Slope instability, Submarine landslides}, isbn = {9789048130702}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79961172106\&partnerID=tZOtx3y1}, author = {Urgeles, R. and Locat, J. and Sawyer, D. E. and Flemings, P. B. and Dugan, B. and Binh, N. T T} } @article {Gracia2010, title = {{Holocene earthquake record offshore Portugal (SW Iberia): testing turbidite paleoseismology in a slow-convergence margin}}, journal = {Quaternary Science Reviews}, volume = {29}, number = {9-10}, year = {2010}, month = {may}, pages = {1156{\textendash}1172}, abstract = {The SW margin of the Iberian Peninsula hosts the present-day boundary between the Eurasian and African Plates. Convergence (4-5 mm/yr) is accommodated through a wide deformation zone characterized by moderate magnitude seismic activity. This zone has also been the source of the most important seismic events in Western Europe, such as the 1755 Lisbon Earthquake and Tsunami and 1969 Horseshoe Earthquake. Despite efforts to identify active seismogenic structures in the Gulf of Cadiz in the last ten years, little is known about its paleoseismic history. The turbidite paleoseismology approach was applied for the first time in a low-rate convergent margin to determine the recurrence interval of large earthquake events that occurred in SW Iberia during the Holocene. Four sediment cores collected at strategically located sites offshore Portugal (i.e. Tagus Abyssal Plain, Infante Don Henrique Basin and Horseshoe Abyssal Plain) reveal that these deep-sea basins preserve a record of episodic deposition of turbidites. In the SW Iberian Margin excluding special climatic events, earthquakes are the most likely triggering mechanism for synchronous, widely-spaced distributed turbidites during the Holocene, when the sea level was relatively stable. Age correlation together with textural, mineralogical, physical properties and geochemical signatures of the new cores complemented by pre-existing multicores and gravity cores reveals a total of 7 widespread turbidite events for the Holocene. Precise dating of the most recent turbidite event (E1) based on 210Pb and 137Cs geochronology provides an age of AD 1971 {\textpm} 3. This age corresponds to a high-magnitude instrumental earthquake in the region: the 1969 Horseshoe Earthquake (Mw 8.0). Calibrated 14C ages of subsequent widespread turbidite events (E3 and E5) correlate with the dates of important historical earthquakes and paleotsunami deposits in the Gulf of Cadiz area, such as AD 1755 and 218 BC, respectively. If older synchronous events (E6, E8, and E10) with ages ranging from 4960-5510 yr BP to 8715-9015 yr BP are also taken into account, a great earthquake recurrence interval of about 1800 years is obtained for the Holocene. Our correlations suggest that the turbidite record may be considered as a proxy for paleoseismic activity in low-convergence rate margins, and a valuable complementary tool in earthquake and tsunami hazard assessment along the coasts of the Iberian Peninsula and North Africa. {\textcopyright} 2010 Elsevier Ltd. All rights reserved.}, issn = {02773791}, doi = {10.1016/j.quascirev.2010.01.010}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77950629573\&partnerID=tZOtx3y1}, author = {Gr{\'a}cia, Eul{\`a}lia and Vizcaino, Alexis and Escutia, Carlota and Asioli, Alessandra and Rod{\'e}s, {\'A}ngel and Pall{\`a}s, Raimon and Garcia-Orellana, Jordi and Lebreiro, Susana and Goldfinger, Chris} } @article {Bartolome2010, title = {{Imaging the Seismic Crustal Structure of the Western Mexican Margin between 19{\textdegree}N and 21{\textdegree}N}}, journal = {Pure and Applied Geophysics}, volume = {168}, number = {8-9}, year = {2010}, month = {nov}, pages = {1373{\textendash}1389}, publisher = {Birkhauser Verlag AG}, abstract = {Three thousand kilometres of multichannel (MCS) and wide-angle seismic profiles, gravity and magnetic, multibeam bathymetry and backscatter data were recorded in the offshore area of the west coast of Mexico and the Gulf of California during the spring 1996 (CORTES survey). The seismic images obtained off Puerto Vallarta, Mexico, in the Jalisco subduction zone extend from the oceanic domain up to the continental shelf, and significantly improve the knowledge of the internal crustal structure of the subduction zone between the Rivera and North American (NA) Plates. Analyzing the crustal images, we differentiate: (1) An oceanic domain with an important variation in sediment thickness ranging from 2.5 to 1 km southwards; (2) an accretionary prism comprised of highly deformed sediments, extending for a maximum width of 15 km; (3) a deformed forearc basin domain which is 25 km wide in the northern section, and is not seen towards the south where the continental slope connects directly with the accretionary prism and trench, thus suggesting a different deformational process; and (4) a continental domain consisting of a continental slope and a mid slope terrace, with a bottom simulating reflector (BSR) identified in the first second of the MCS profiles. The existence of a developed accretionary prism suggests a subduction-accretion type tectonic regime. Detailed analysis of the seismic reflection data in the oceanic domain reveals high amplitude reflections at around 6 s [two way travel time (twtt)] that clearly define the subduction plane. At 2 s (twtt) depth we identify a strong reflection which we interpret as the Moho discontinuity. We have measured a mean dip angle of 7{\textdegree} {\textpm} 1{\textdegree} at the subduction zone where the Rivera Plate begins to subduct, with the dip angle gently increasing towards the south. The oceanic crust has a mean crustal thickness of 6.0-6.5 km. We also find evidence indicating that the Rivera Plate possibly subducts at very low angles beneath the Tres Marias Islands. {\textcopyright} 2010 Springer Basel AG.}, keywords = {BSR, Crustal structure, Middle America Trench, Rivera Plate, Seismic imaging, Subduction plate}, issn = {0033-4553}, doi = {10.1007/s00024-010-0206-x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905116997\&partnerID=tZOtx3y1}, author = {Bartolom{\'e}, Rafael and Da{\~n}obeitia, Juanjo and Michaud, Fran{\c c}ois and C{\'o}rdoba, Diego and Delgado-Argote, Luis A.} } @article {Garcia2010, title = {{In vitro characterization and in vivo analgesic and anti-allodynic activity of PLGA-bupivacaine nanoparticles}}, journal = {Journal of Nanoparticle Research}, volume = {13}, number = {5}, year = {2010}, month = {jun}, pages = {2213{\textendash}2223}, abstract = {An injectable controlled release system containing local anesthetics able to provide longlasting analgesia in nociceptive and neuropathic pain could have a marked impact in pain management. In order to address this issue, bupivacaine, a widely used local anesthetic, has been nanoencapsulated using poly(lactic-co-glycolic acid) from an oil-in-water emulsion by the solvent evaporation technique. Nanoparticles were evaluated in vitro studying their drug release mechanism by fitting different model equations, and in vivo by testing its analgesic and anti-allodynic activity in front of heat-induced nociceptive pain and sciatic nerve chronic constriction injury in rats, respectively. The particle size of the PLGA nanoparticles obtained was of 453 {\textpm} 29 nm, the encapsulation efficiency, drug loading, and burst effect at 30 min were 82.10 {\textpm} 0.001, 45.06 {\textpm} 0.001, and 4.6 {\textpm} 0.6\%, respectively. A prolonged release of the drug in comparison to bupivacaine solution was seen. The mean dissolution time (MDT) obtained for nanoparticles was relatively long (9.44 {\textpm} 0.56 h) proving the sustained release process, while the dissolution efficiency (DE) (84.10 {\textpm} 1.01\%) was similar to the maximum percentage of drug released. Korsmeyer- Peppas was the best model that fitted our release data.A non-Fickian mechanism was concluded to be involved in the release of bupivacaine from the nanoparticles, taking into account the value of the diffusional exponent obtained (n = 0.95). After local infiltration in the rat, the antinociceptive and anti-allodynic activity of the nanoencapsulated bupivacaine was longer lasting than that of bupivacaine solution. An increase in the values of the area under the curve (AUC) of the antinociceptive and anti-allodynic effect versus time of 67 and 36\%, respectively, was observed when the drug was encapsulated. {\textcopyright} Springer Science+Business Media B.V. 2010.}, keywords = {Antiallodynia, Antinociception, Bupivacaine, In vitro release, Korsmeyer-peppas, Modeling and simulation, Nanomedicine, Plga nanoparticles}, issn = {1388-0764}, doi = {10.1007/s11051-010-9979-1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79956290523\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Escribano, Elvira and Domenech, Josep and Queralt, Josep and Freixes, Joan} } @article {Garcia2010b, title = {{Internal structure of the western flank of the Cumbre Vieja volcano, La Palma, Canary Islands, from land magnetotelluric imaging}}, journal = {Journal of Geophysical Research}, volume = {115}, number = {B7}, year = {2010}, month = {jul}, pages = {B07104}, abstract = {Large-scale mass wasting is a natural part of the evolution of volcanic islands, where deformation and indications of flank instability, such as large-scale faulting and seismic and aseismic slip are common. The Cumbre Vieja volcano on the island of La Palma (Canary Islands) provides an ideal setting to address fundamental questions about the structure, evolution and stability of island volcanoes. The island of La Palma is still in a shield-building stage, and it has been postulated that the western side of the island lies over a pre-existing zone of weakness that can nucleate ruptures. We undertook an audiomagnetotelluric (AMT) survey over the proposed unstable western flank to try to image structures that may be associated with the zone of weakness. The magnetotelluric method (MT) is a geophysical technique used to map the presence of fluids or image important structural contrasts. The goals of this study were (1) to delineate the unstable flank, (2) to map the structures underneath and (3) to determine the presence and geometry of fluids. The results show a 1 km thick top resistive layer overlaying an area of reduced resistivity (enhanced conductivity), interpreted as a layer consisting of an alteration zone and also fluids. Our results confirm previous studies that suggested the existence of a western flank lying over collapse debris material and hyaloclastites, and also they allow us to map part of the subaerial southern extent of the Cumbre Nueva units that lie beneath the more recent Cumbre Vieja rocks. In addition, dimensionality analysis maps the rotation of the dike emplacement off ridge, along the western flank in an en echelon fashion.Copyright 2010 by the American Geophysical Union.}, issn = {0148-0227}, doi = {10.1029/2009JB006445}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955204988\&partnerID=tZOtx3y1}, author = {Garcia, X. and Jones, A. G.} } @article {LoIacono2010, title = {{Large-scale bedforms along a tideless outer shelf setting in the western Mediterranean}}, journal = {Continental Shelf Research}, volume = {30}, number = {17}, year = {2010}, month = {oct}, pages = {1802{\textendash}1813}, abstract = {High-resolution multibeam swath-bathymetry and sediment samples were collected across the outer shelf region of the Columbretes Islands (southern Ebro continental shelf, western Mediterranean Sea). Bathymetric data from the submerged part of the Columbretes volcanic system revealed the presence of three main relict sand bodies along the outer shelf, at 80-116. m depth range, above which asymmetric and slightly asymmetric large and very large 2D and 3D subaqueous dunes were observed. These bed features were recognized, mapped and quantified with the aim of evaluating their potential formation mechanisms in relation to the local hydrodynamic and morphologic settings of the area. Dunes range from 150 to 760. m in wavelength and from tens of centimeters to 3. m in height, and are among the longest ever recognized in an outer shelf region. These bedforms are mostly composed of medium-sized sandy sediments, presumably coming from the degraded relict sand bodies on top of which they have developed, mixed with fine fractions from the recent draping holocenic sediments. The orientation of the dunes is SSW, progressively turning W towards the southernmost sector of the area, following the trend of the shelf-edge. Contemporary hydrodynamic measurements at the Ebro continental shelf-edge show that recorded currents are insufficient to form the observed bedforms and that stronger currents are required for sediment mobilization and dune formation. Based on their morphology and orientation, it is proposed that these bedforms are produced by the action of the southward-flowing Liguro-Proven{\c c}al-Catalan (LPC) geostrophic current. The LPC probably reaches high near-bottom currents during energetic hydrodynamic events through interactions with the seafloor morphology of the study area. Subaqueous dunes are expected to be basically inactive features with respect to present-day processes, although they can be reactivated during high-energy events. The small $Δ$h/${\l}ambda$ ratio measured in the dune fields of the Columbretes shelf revealed that the dune heights fall below the values predicted by the Flemming (1988) global equation, as observed in other outer shelf settings also dominated by unidirectional flows. This may suggest a different morphodynamic character of large dunes formed on outer shelves in a micro-tidal regime. {\textcopyright} 2010 Elsevier Ltd.}, keywords = {Continental shelf, Geomorphology, Subaqueous dunes, Swath mapping, Western Mediterranean}, issn = {02784343}, doi = {10.1016/j.csr.2010.08.005}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957596289\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Guill{\'e}n, Jorge and Puig, Pere and Rib{\'o}, Marta and Ballesteros, Maria and Palanques, Albert and l{\'\i} Farr{\'a}n, Marcel and Acosta, Juan} } @mastersthesis {Cameselle2010, title = {{Mapping of Sedimentary Bodies by 3D Seismic Reflection Data: Application to the pre-Messinian Ebro Margin}}, number = {September}, year = {2010}, school = {Universitat de Barcelona \{\&\} Universitat Ram\{\'o}\}n Llull}, type = {phd}, author = {Cameselle, Alejandra L} } @conference {Tahchi2010, title = {{Mass wasting at the easternmost Cyprus Arc, Off Syria, Eastern Mediterranean}}, booktitle = {Submarine Mass Movements and Their Consequences - 4th International Symposium}, year = {2010}, pages = {323{\textendash}334}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, abstract = {The seafloor topography at the easternmost deformation front between the African and the Anatolian plate off Syria is dominated by the Latakia Ridge, which obliquely intersects the Syrian margin. In this study, we investigate post-Miocene depositional processes of this topographically intricate area and their relationship with mass-wasting phenomena by means of bathymetric, multi-channel seismic reflection and sediment sub-bottom profiler data. Northward of the Latakia Ridge, the Latakia Slope is characterized by steep scarps of up to 500 m height. The Pliocene-Quaternary strata are truncated by the scarps, which are located in the upward prolongation of normal fault planes. Some scarps are from erosion or non-deposition as a consequence of contour currents. Evidence for recent active tectonics is also present in the Latakia Ridge. A basement outcrop along the crest of the northern Latakia Ridge presumably reflects the transtensional faulting of this easternmost section of the African-Anatolian deformation front. The western side of the northern Latakia Ridge shows evidence of more cohesive slumping, probably owing to the overconsolidated nature of the sediment. Here a potential future slide of 11 km3 associated with a rotational fault has been identified. The sedimentary and tectonic setting has resulted in frequent mass wasting. Abundant scars and debris flow-like deposits have been observed on the flanking slopes of the Latakia canyon and the Syrian Margin. The Latakia canyon is fed by several tributary canyons which are incised into the Syrian Slope. Steep slopes, high sediment accumulation rates and active strike-slip tectonics appear to have a fundamental role in submarine mass-failure initiation. Mass-failure characteristics indicate that geohazards may exist from subsequent potential tsunami generation. {\textcopyright} Springer Science + Business Media B.V. 2010.}, keywords = {Contour current, Debris-flow deposits, Mass failure, Seafloor bathymetry, Syrian Margin}, isbn = {9789048130702}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903484606\&partnerID=tZOtx3y1}, author = {Tahchi, E. and Urgeles, R. and H{\"u}bscher, C. and Benkhelil, J.} } @booklet {Moreno2013, title = {{Onshore-Offshore active tectonics along the Carboneras Fault Zone (Eastern Betic Cordilleras)}}, journal = {Contribuci{\'o}n de la Geolog{\'\i}a al An{\'a}lisis de la Peligrosidad S{\'\i}smica}, year = {2010}, month = {sep}, pages = {105{\textendash}107}, abstract = {Primera Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a. Sig{\"u}enza (Guadalajara, Espa{\~n}a) 27, 28 y 29 de Octubre de 2010.{\textendash} 3 pages, 1 figure}, isbn = {isbn: 978-84-693-6088-0}, url = {http://digital.csic.es/handle/10261/82454}, author = {Moreno, Ximena and Masana, Eul{\`a}lia and Gr{\'a}cia, Eul{\`a}lia and Bartolom{\'e}, R and Rod{\'e}s, {\'A}ngel and Pall{\`a}s, Raimon} } @conference {DeLaPuente2010, title = {{The potential of discontinuous Galerkin methods for full waveform tomography}}, booktitle = {72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010}, volume = {6}, year = {2010}, pages = {4144{\textendash}4148}, abstract = {We present a discontinuous Galerkin solver for Full Waveform Tomography applications in seismic exploration. We discuss the advantages and drawbacks of using unstructured meshes in the model discretization and present a numerical example. {\textcopyright} 2010, European Association of Geoscientists and Engineers.}, isbn = {9781617386671}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78249285605\&partnerID=tZOtx3y1}, author = {De La Puente, J. and Sallar{\`e}s, V. and Ranero, C. R.} } @article {Biescas2010, title = {{Seismic imaging of staircase layers below the Mediterranean Undercurrent}}, journal = {Deep Sea Research Part I: Oceanographic Research Papers}, volume = {57}, number = {10}, year = {2010}, month = {oct}, pages = {1345{\textendash}1353}, abstract = {Seismic images of staircase layers at the bottom of the Mediterranean Undercurrent with a lateral coherence up to 50. km and a horizontal resolution of \~{}10m are presented. The images show clearly the interaction between these staircase layers and other flow structures such as meddies, seamounts and internal waves. The staircase layers were imaged during two different surveys that used different sound sources. Comparison between seismic images and historical oceanographic observations illustrates the importance of using a seismic source adapted to the vertical scale of the oceanographic target to be imaged. Wavelengths larger than the size of the staircase structure distort the image in the vertical. For optimal imaging, deconvolution of the data is required. {\textcopyright} 2010 Elsevier Ltd.}, keywords = {Boundary mixing, Gulf of Cadiz, Meddy, Mediterranean Undercurrent, Seismic oceanography, Thermohaline staircase layers}, issn = {09670637}, doi = {10.1016/j.dsr.2010.07.001}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956879722\&partnerID=tZOtx3y1}, author = {Biescas, Berta and Armi, Larry and Sallares, Valenti and Gr{\'a}cia, Eul{\`a}lia} } @article {Dannowski2010, title = {{Seismic structure of an oceanic core complex at the Mid-Atlantic Ridge, 22{\textdegree}19'N}}, journal = {Journal of Geophysical Research}, volume = {115}, number = {B7}, year = {2010}, month = {jul}, pages = {B07106}, abstract = {We present results from a seismic refraction and wide-angle experiment surveying an oceanic core complex on the Mid-Atlantic Ridge at 2219N. Oceanic core complexes are settings where petrological sampling found exposed lower crustal and upper mantle rocks, exhumed by asymmetric crustal accretion involving detachment faulting at magmatically starved ridge sections. Tomographic inversion of our seismic data yielded lateral variations of P wave velocity within the upper 3 to 4 km of the lithosphere across the median valley. A joint modeling procedure of seismic P wave travel times and marine gravity field data was used to constrain crustal thickness variations and the structure of the uppermost mantle. A gradual increase of seismic velocities from the median valley to the east is connected to aging of the oceanic crust, while a rapid change of seismic velocities at the western ridge flank indicates profound differences in lithology between conjugated ridge flanks, caused by un-roofing lower crust rocks. Under the core complex crust is approximately 40\% thinner than in the median valley and under the conjugated eastern flank. Clear PmP reflections turning under the western ridge flank suggest the creation of a Moho boundary and hence continuous magmatic accretion during core complex formation.Copyright 2010 by the American Geophysical Union.}, issn = {0148-0227}, doi = {10.1029/2009JB006943}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955209693\&partnerID=tZOtx3y1}, author = {Dannowski, Anke and Grevemeyer, Ingo and Ranero, Cesar R. and Ceuleneer, Georges and Maia, Marcia and Morgan, Jason Phipps and Gente, Pascal} } @article {Ranero2010, title = {{Sequential faulting explains the asymmetry and extension discrepancy of conjugate margins.}}, journal = {Nature}, volume = {468}, number = {7321}, year = {2010}, month = {nov}, pages = {294{\textendash}9}, abstract = {During early extension, cold continental lithosphere thins and subsides, creating rift basins. If extension continues to final break-up, the split and greatly thinned plates subside deep below sea level to form a conjugate pair of rifted margins. Although basins and margins are ubiquitous structures, the deformation processes leading from moderately extended basins to highly stretched margins are unclear, as studies consistently report that crustal thinning is greater than extension caused by brittle faulting. This extension discrepancy might arise from differential stretching of brittle and ductile crustal layers, but that does not readily explain the typical asymmetric structure of conjugate margins-in cross-section, one margin displays gradual thinning accompanied by large faults, and the conjugate margin displays abrupt thinning but smaller-scale faulting. Whole-crust detachments, active from early in the rifting, could in theory create both thinning and asymmetry, but are mechanically problematical. Furthermore, the extension discrepancy occurs at both conjugate margins, leading to the apparent contradiction that both seem to be upper plates to a detachment fault. Alternative models propose that much brittle extension is undetected because of seismic imaging limitations caused either by subseismic-resolution faulting, invisible deformation along top-basement 100-km-scale detachments or the structural complexity of cross-cutting arrays of faults. Here we use depth-migrated seismic images to accurately measure fault extension and compare it with crustal thinning. The observations are used to create a balanced kinematic model of rifting that resolves the extension discrepancy by producing both fault-controlled crustal thinning which progresses from a rift basin to the asymmetric structure, and extreme thinning of conjugate rifted margins. Contrary to current wisdom, the observations support the idea that thinning is to a first degree explained by simple Andersonian faulting that is unambiguously visible in seismic data.}, issn = {1476-4687}, doi = {10.1038/nature09520}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78149470133\&partnerID=tZOtx3y1}, author = {Ranero, C{\'e}sar R and P{\'e}rez-Gussiny{\'e}, Marta} } @article {Bernabeu2010, title = {{Simulating the influence of physicochemical parameters on subsurface oil on beaches: preliminary results.}}, journal = {Marine pollution bulletin}, volume = {60}, number = {8}, year = {2010}, month = {aug}, pages = {1170{\textendash}1174}, publisher = {Elsevier Ltd}, abstract = {Monitoring of sandy beaches after the Prestige oil spill revealed thick subsurface layers (up to 1m thick) of grey-coloured sand. These horizons were sometimes found under more than 3m of clean sand. Examination of the sand by electron microscopy confirmed that the colouring was due to oil-coated sand grains, and revealed a sequence of degradation of buried oil. Further analysis of the sand revealed high concentrations of hydrocarbon in the oil-coated sand and that the main biomarkers were indicative of biodegradation, even though the oil was buried. A set of experiments was designed to analyze the evolution of oil from tar balls to coatings. The results revealed that biodegradation is a secondary process in the changes that take place in the buried oil, and that water flow slows down the appearance of grey sand and that low salinity may hinder the oil degradation process.}, keywords = {Bathing Beaches, Biodegradation, Chemical, Chemical Hazard Release, Environmental, Environmental Monitoring, Kinetics, Models, Petroleum, Petroleum: analysis, Petroleum: metabolism, Silicon Dioxide, Silicon Dioxide: chemistry}, issn = {1879-3363}, doi = {10.1016/j.marpolbul.2010.04.001}, url = {http://www.ncbi.nlm.nih.gov/pubmed/20451931}, author = {Bernabeu, Ana M and Rey, D and Lago, A and Vilas, F} } @article {Buffett2010, title = {{Stochastic heterogeneity mapping around a mediterranean salt lens}}, journal = {Ocean Science}, volume = {6}, number = {1}, year = {2010}, pages = {423{\textendash}429}, abstract = {We present the first application of Stochastic Heterogeneity Mapping based on the band-limited von K{\'a}rm{\'a}n function to a seismic reflection stack of a Mediterranean water eddy (meddy), a large salt lens of Mediterranean water. This process extracts two stochastic parameters directly from the reflectivity field of the seismic data: the Hurst number, which ranges from 0 to 1, and the correlation length (scale length). Lower Hurst numbers represent a richer range of high wavenumbers and correspond to a broader range of heterogeneity in reflection events. The Hurst number estimate for the top of the meddy (0.39) compares well with recent theoretical work, which required values between 0.25 and 0.5 to model internal wave surfaces in open ocean conditions based on simulating a Garrett-Munk spectrum (GM76) slope of \&-2. The scale lengths obtained do not fit as well to seismic reflection events as those used in other studies to model internal waves. We suggest two explanations for this discrepancy: (1) due to the fact that the stochastic parameters are derived from the reflectivity field rather than the impedance field the estimated scale lengths may be underestimated, as has been reported; and (2) because the meddy seismic image is a two-dimensional slice of a complex and dynamic three-dimensional object, the derived scale lengths are biased to the direction of flow. Nonetheless, varying stochastic parameters, which correspond to different spectral slopes in the Garrett-Munk spectrum (horizontal wavenumber spectrum), can provide an estimate of different internal wave scales from seismic data alone. We hence introduce Stochastic Heterogeneity Mapping as a novel tool in physical oceanography.}, issn = {18120784}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77950468840\&partnerID=tZOtx3y1}, author = {Buffett, G. G. and Hurich, C. A. and Vsemirnova, E. A. and Hobbs, R. W. and Sallar{\`e}s, V. and Carbonell, R. and Klaeschen, D. and Biescas, B.} } @booklet {Perea2013, title = {{Structure and Potential Seismogenic Sources of the Offshore Bajo Segura Fault Zone, Se Iberian Peninsula (Mediterranean Sea). Looking for the Source of the 1829 Torrevieja Earthquake}}, journal = {Res{\'u}menes de la 1{\textordfeminine} Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a, Sig{\"u}enza, Espa{\~n}a}, year = {2010}, month = {sep}, pages = {113{\textendash}116}, abstract = {Primera Reuni{\'o}n Ib{\'e}rica sobre Fallas Activas y Paleosismolog{\'\i}a. Sig{\"u}enza (Guadalajara, Espa{\~n}a) 27, 28 y 29 de Octubre de 2010.{\textendash} 4 pages, 4 figures}, keywords = {abstract, almost a, bajo segura, been extensively studied, betic shear zone and, bsfz, complete lack of information, during the event-shelf cruise, extends further, fallas activas, from a tectonic point, geolog{\'\i}a marina, into the mediterranean sea, is the northern terminal, of the bsfz has, of view, splay of the eastern, tect{\'o}nica activa, ten high-resolution seismic profiles, the bajo segura fault, the offshore zone has, whereas the onshore zone, zone}, isbn = {isbn: 978-84-693-6088-0}, url = {http://digital.csic.es/handle/10261/82456}, author = {Perea, H. and Gr{\`a}cia, E. and Bartolom{\'e}, Rafael and Iacono, Claudio Lo and Masana, E.} } @article {GarciaX.Jones2010, title = {{Structure of an unstable, Atlantic Oceanic island volcano (La Palma, Canary Islands) from land magnetotelluric imaging}}, journal = {Journal of Geophysical Research}, volume = {B7}, year = {2010}, pages = {115}, doi = {10.1029/2009JB006445}, url = {http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2008/08835/EGU2008-A-08835.pdf}, author = {Garcia, X., Jones, A.G.} } @conference {Urgeles2013a, title = {{Submarine Landslides and Tsunamis}}, booktitle = {Earth and Planetary Sciences}, volume = {21}, year = {2010}, pages = {69{\textendash}88}, keywords = {landslide, landslides, rigid body, subaerial, submarine, Submarine landslide, Submarine landslides, submarine-landslide, submarine-landslides, tsunami, tsunamis, viscous slide}, isbn = {1402013493}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84898728287\&partnerID=tZOtx3y1}, author = {Yalciner, a C and Pelinovsky, E N and Okal, E and Synolakis, C} } @inbook {Mosher2010, title = {{Submarine mass movements and their consequences}}, booktitle = {Submarine Mass Movements and Their Consequences, Advances in Natural and Technological Hazards Research}, year = {2010}, pages = {1{\textendash}8}, publisher = {Kluwer Academic Publishers}, organization = {Kluwer Academic Publishers}, isbn = {9789048130702}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903442067\&partnerID=tZOtx3y1}, author = {Mosher, D. C. and Moscardelli, L. and Shipp, R. C. and Chaytor, J. D. and Baxter, C. D P and Lee, H. J. and Urgeles, R.} } @book {Mosher2010a, title = {{Submarine Mass Movements and Their Consequences: 4 rd International Symposium. Advances in Natural and Technological Hazards Research: v. 28}}, series = {Submarine Mass Movements and Their Consequences: 4 rd International Symposium}, year = {2010}, pages = {786}, url = {http://scholar.google.es/scholar?q=Advances+in+Natural+and+Technological+Hazards+Research+Moscardelli\&btnG=\&hl=es\&as\_sdt=0\%2C5\#9}, author = {Mosher, DC and Shipp, RC and Moscardelli, L} } @article {Kormann2010, title = {{Synthetic modelling of acoustical propagation applied to seismic oceanography experiments}}, journal = {Geophysical Research Letters}, volume = {37}, number = {6}, year = {2010}, month = {mar}, pages = {n/a{\textendash}n/a}, abstract = {Recent work shows that multichannel seismic (MCS) systems provide detailed information on the oceans{\textquoteright} finestructure. The aim of this paper is to analyze if high order numerical algorithms are suitable to accurately model the extremely weak wavefield scattered by the oceans{\textquoteright} finestructures. For this purpose, we generate synthetic shot records along a coincident seismic and oceanographic profile acquired across a Mediterranean salt lens in the Gulf of Cadiz. We apply a 2D finite-difference time-domain propagation model, together with second-order Complex Frequency Shifted Perfectly Matched Layers at the numerical boundaries, using as reference a realistic sound speed map with the lateral resolution of the seismic data. We show that our numerical propagator creates an acoustical image of the ocean finestructures including the salt lens that reproduces with outstanding detail the real acquired one. Copyright {\textcopyright} 2010 by the American Geophysical Union.}, issn = {00948276}, doi = {10.1029/2009GL041763}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77949835265\&partnerID=tZOtx3y1}, author = {Kormann, Jean and Cobo, Pedro and Biescas, Berta and Sallares, Valenti and Papenberg, Cord and Recuero, Manuel and Carbonell, Ram{\'o}n} } @article {Falivene2010, title = {{Synthetic seismic models from outcrop-derived reservoir-scale three-dimensional facies models: The Eocene Ainsa turbidite system (southern Pyrenees)}}, journal = {AAPG Bulletin}, volume = {94}, number = {3}, year = {2010}, month = {mar}, pages = {317{\textendash}343}, abstract = {This study uses one-dimensional convolution seismic models to better understand which features of slope turbidite systems can (or cannot) be observed on real seismic data, aiming to improve subsurface seismic interpretation. Synthetic seismic sections and cubes were built from reservoir-scale three-dimensional fades models of the outcropping Ainsa turbidite system. This turbidite system developed in a foredeep and wedge-top depositional setting within a slope system. The turbidite system consists of laterally and vertically stacked sandstone- and debrite-dominated channel fills, grading into heterolithic and mudstone units, with intercalations of slump-deformed mudstone-rich units. Typical petrophysical values for subsurface Cenozoic sediments were assumed for the seismic models, which are presented at 25-, 50-, and 75-Hz resolution. Seismic models enabled the comparison between architectural and faci{\`e}s distributions observed in the outcrops and the geological models to their possible seismic expression in the subsurface. Comparisons show how seismic expression degrades when seismic resolution decreases. By using models at different geological scales, the effects of each heterogeneity scale are identified. Precise delineation of the internal architecture and fades distribution within channel complexes is beyond the reach of all seismic frequendes. The position of channel complex tops and margins is uncertain because of thengradual character. Differentiating between sandstone- and debrite-filled channels is not straightforward, and bed-scale heterogendties within the sandstone-dominated channels are barely distinguishable in the seismic data. The net-to-gross predictive capability of root-mean-square amplitude extractions varies depending on the seismic frequency and unit thickness. Copyright {\textcopyright} 2010. The American Association of Petroleum Geologists All rights reserved.}, issn = {0149-1423}, doi = {10.1306/08030908157}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77950302966\&partnerID=tZOtx3y1}, author = {Falivene, O. and Arbu{\'e}s, P. and Ledo, J. and Benjumea, B. and Mu{\~n}oz, J. A. and Fern{\'a}ndez, O. and Mart{\'\i}nez, S.} } @article {Harris2010a, title = {{Thermal regime of the Costa Rican convergent margin: 1. Along-strike variations in heat flow from probe measurements and estimated from bottom-simulating reflectors}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {11}, number = {12}, year = {2010}, month = {dec}, pages = {n/a{\textendash}n/a}, abstract = {The thermal structure of convergent margins provides information related to the tectonics, geodynamics, metamorphism, and fluid flow of active plate boundaries. We report 176 heat flow measurements made with a violin bow style probe across the Costa Rican margin at the Middle America Trench. The probe measurements are collocated with seismic reflection lines. These seismic reflection lines show widespread distribution of bottom-simulating reflectors (BSRs). To extend the spatial coverage of heat flow measurements we estimate heat flow from the depth of BSRs. Comparisons between probe measurements and BSR-derived estimates of heat flow are generally within 10\% and improve with distance landward of the deformation front. Together, these determinations provide new information on the thermal regime of this margin. Consistent with previous studies, the margin associated with the northern Nicoya Peninsula is remarkably cool. We define better the southern boundary of the cool region. The northern extent of the cool region remains poorly determined. A regional trend of decreasing heat flow landward of the deformation front is apparent, consistent with the downward advection of heat by the subducting Cocos Plate. High wave number variability at a scale of 5-10 km is significantly greater than the measurement uncertainty and is greater south of the northern Nicoya Peninsula. These heat flow anomalies vary between approximately 20 and 60 mW m-2 and are most likely due to localized fluid flow through mounds and faults on the margin. Simple one-dimensional models show that these anomalies are consistent with flow rates of 7-15 mm yr-1. Across the margin toe variability is significant and likely due to fluid flow through deformation structures associated with the frontal sedimentary prism. Copyright 2010 by the American Geophysical Union.}, keywords = {fluid flow, heat flow, Middle America Trench, subduction zones}, issn = {15252027}, doi = {10.1029/2010GC003272}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78650544794\&partnerID=tZOtx3y1}, author = {Harris, Robert N. and Grevemeyer, Ingo and Ranero, Cesar R. and Villinger, Heinrich and Barckhausen, Udo and Henke, Thomas and Mueller, Christian and Neben, Soenke} } @article {Harris2010, title = {{Thermal regime of the Costa Rican convergent margin: 2. Thermal models of the shallow Middle America subduction zone offshore Costa Rica}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {11}, number = {12}, year = {2010}, month = {dec}, pages = {n/a{\textendash}n/a}, abstract = {At the Costa Rica margin along the Middle America Trench along-strike variations in heat flow are well mapped. These variations can be understood in terms of either ventilated fluid flow, where exposed basement allows fluids to freely advect heat between the crustal aquifer and ocean, or insulated fluid flow where continuous sediment cover restricts heat advection to within the crustal aquifer. We model fluid flow within the subducting aquifer using Nusselt number approximations coupled with finite element models of subduction and explore its effect on temperatures along the subduction thrust. The sensitivity of these models to the initial thermal state of the plate and styles of fluid flow, either ventilated or insulated, is explored. Heat flow measurements on cool crust accreted at the East Pacific Rise are consistent with ventilated hydrothermal cooling that continues with subduction. These models yield much cooler temperatures than predicted from simulations initialized with conductive predictions and without hydrothermal circulation. Heat flow transects on warm crust accreted at the Cocos-Nazca spreading center are consistent with models of insulated hydrothermal circulation that advects heat updip within the subducting crustal aquifer. Near the trench these models are warmer than conductive predictions and cooler than conductive predictions downdip of the trench. Comparisons between microseismicity and modeled isotherms suggest that the updip limit of microseismicity occurs at temperatures warmer than 100{\textdegree}C and that the downdip extent of microseismicity is bounded by the intersection of the subduction thrust with the base of the overriding crust. Copyright 2010 by the American Geophysical Union.}, keywords = {fluid flow, subduction zones, thermal model}, issn = {15252027}, doi = {10.1029/2010GC003273}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78650528793\&partnerID=tZOtx3y1}, author = {Harris, Robert N. and Spinelli, Glenn and Ranero, Cesar R. and Grevemeyer, Ingo and Villinger, Heinrich and Barckhausen, Udo} } @booklet {LoIacono2010a, title = {{Very high-resolution seismo-acoustics in the study of seagrasses. The case of posidonia oceanica (Mediterranean sea)}}, year = {2010}, month = {mar}, publisher = {SARTI (Technological Development Centre of Remote Acquisition and Data processing Systems)}, abstract = {The study of active structures offshore requires very-high resolution seismic imaging in order to observe the most recent layers below sea floor. In the other hand, high penetration methods are necessary to observe deeper reflections for understanding the evolution of the structure throughout the time. The aim of our study is to establish the seismic potential of the offshore segment of the Carboneras Fault, Eastern Betics, based on multiscale seismic imaging. Three different scale methods have been acquired and are compared here: very-high-resolution sub-bottom profiler TOPAS, very-high-resolution single-channel seismic (Sparker) and high-resolution multi-channel seismic. From seismic profiles, faulted Quaternary layers suggest that the Carboneras Fault is active. Sediment coring and dating analysis are used to consider ages for key reflectors observed in TOPAS profiles, and a change in the vertical slip-rate through the Quaternary is inferred.}, keywords = {{\`A}rees tem{\`a}tiques de la UPC::Enginyeria electr{\`o}nica, Holocene, Mediterranean Sea, Non linear seismo-acoustics, Seagrasses}, url = {http://upcommons.upc.edu//handle/2099/8613}, author = {Lo Iacono, Claudio and Gr{\'a}cia, Eul{\`a}lia and Da{\~n}obeitia, Juan Jos{\'e}} } @article {Munjiza2010, title = {{The Virtual Geoscience Workbench, VGW: Open Source tools for discontinuous systems}}, journal = {Particuology}, volume = {8}, number = {2}, year = {2010}, month = {apr}, pages = {100{\textendash}105}, abstract = {In 1989 work began on merging finite and discrete elements. During 1990 algorithmic solutions for the new combined method were developed, together with a C-based implementation known as the Y code. In 2004 these developments and implementations were published as a textbook. Queen Mary University of London (QMUL) and Imperial College are currently engaged in a research project to make Y codes in both 2D and 3D available in Open Source format and with mainly geoscience problems in mind. The result is a set of Open Source tools for Geoscience (VGW), key components of which are summarised in this paper, together with illustrative range of simulation results. {\textcopyright} 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.}, keywords = {Combined finite-discrete element, Geoscience, Modelling, Workbench}, issn = {16742001}, doi = {10.1016/j.partic.2009.04.008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77949485463\&partnerID=tZOtx3y1}, author = {Munjiza, A. and XIANG, J. and Garcia, X. and Latham, J.P. and D{\textquoteright}Albano, G.G. Schiava and John, N.W.M.} } @article {Jones2009, title = {{Area selection for diamonds using magnetotellurics: Examples from southern Africa}}, journal = {Lithos}, volume = {112}, year = {2009}, month = {nov}, pages = {83{\textendash}92}, abstract = {Southern Africa, particularly the Kaapvaal Craton, is one of the world{\textquoteright}s best natural laboratories for studying the lithospheric mantle given the wealth of xenolith and seismic data that exist for it. The Southern African Magnetotelluric Experiment (SAMTEX) was launched to complement these databases and provide further constraints on physical parameters and conditions by obtaining information about electrical conductivity variations laterally and with depth. Initially it was planned to acquire magnetotelluric data on profiles spatially coincident with the Kaapvaal Seismic Experiment, however with the addition of seven more partners to the original four through the course of the experiment, SAMTEX was enlarged from two to four phases of acquisition, and extended to cover much of Botswana and Namibia. The complete SAMTEX dataset now comprises MT data from over 730 distinct locations in an area of over one million square kilometres, making SAMTEX the largest regional-scale MT experiment conducted to date. Preliminary images of electrical resistivity and electrical resistivity anisotropy at 100 km and 200 km, constructed through approximate one-dimensional methods, map resistive regions spatially correlated with the Kaapvaal, Zimbabwe and Angola Cratons, and more conductive regions spatially associated with the neighbouring mobile belts and the Rehoboth Terrane. Known diamondiferous kimberlites occur primarily on the boundaries between the resistive or isotropic regions and conductive or anisotropic regions. Comparisons between the resistivity image maps and seismic velocities from models constructed through surface wave and body wave tomography show spatial correlations between high velocity regions that are resistive, and low velocity regions that are conductive. In particular, the electrical resistivity of the sub-continental lithospheric mantle of the Kaapvaal Craton is determined by its bulk parameters, so is controlled by a bulk matrix property, namely temperature, and to a lesser degree by iron content and composition, and is not controlled by contributions from interconnected conducting minor phases, such as graphite, sulphides, iron oxides, hydrous minerals, etc. This makes quantitative correlations between velocity and resistivity valid, and a robust regression between the two gives an approximate relationship of Vs [m/s] = 0.045 * log(resistivity [ohm m]) + 4.5. {\textcopyright} 2009.}, keywords = {Cratonic lithosphere, Diamond exploration, Electrical conductivity, Kaapvaal Craton, Sub-continental lithospheric mantle, Zimbabwe Craton}, issn = {00244937}, doi = {10.1016/j.lithos.2009.06.011}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72149117671\&partnerID=tZOtx3y1}, author = {Jones, Alan G. and Evans, Rob L. and Muller, Mark R. and Hamilton, Mark P. and Miensopust, Marion P. and Garcia, Xavier and Cole, Patrick and Ngwisanyi, Tiyapo and Hutchins, David and Fourie, C.J.S. and Jelsma, Hielke and Evans, Shane and Aravanis, Theo and Pettit, Wayne and Webb, Sue and Wasborg, Jan} } @article {TRIGO-RODRIGUEZ2009, title = {{The Cali meteorite fall: A new H/L ordinary chondrite}}, journal = {Meteoritics \& Planetary Science}, volume = {44}, number = {2}, year = {2009}, month = {feb}, pages = {211{\textendash}220}, abstract = {The fall of the Cali meteorite took place on 6 July 2007 at 16 h 32 {\textpm} 1 min local time (21 h 32 {\textpm} 1 min UTC). A daylight fireball was witnessed by hundreds of people in the Cauca Valley in Colombia from which 10 meteorite samples with a total mass of 478 g were recovered near 3{\textdegree}24.3{\textquoteright}N, 76{\textdegree}30.6{\textquoteright}W. The fireball trajectory and radiant have been reconstructed with moderate accuracy. From the computed radiant and from considering various plausible velocities, we obtained a range of orbital solutions that suggest that the Cali progenitor meteoroid probably originated in the main asteroid belt. Based on petrography, mineral chemistry, magnetic susceptibility, fhermoluminescence, and bulk chemistry, the Cali meteorite is classified as an H/L4 ordinary chondrite breccia.}, issn = {10869379}, doi = {10.1111/j.1945-5100.2009.tb00729.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-65949113395\&partnerID=tZOtx3y1}, author = {TRIGO-RODR{\'I}GUEZ, Josep M. and LLORCA, Jordi and RUBIN, Alan E. and GROSSMAN, Jeffrey N. and SEARS, Derek W. G. and NARANJO, Mateo and BRETZIUS, Stacy and TAPIA, Mar and SEP{\'U}LVEDA, Marino H. GUAR{\'I}N} } @article {Perea2009, title = {{The Catalan seismic crisis (1427 and 1428; NE Iberian Peninsula): Geological sources and earthquake triggering}}, journal = {Journal of Geodynamics}, volume = {47}, number = {5}, year = {2009}, month = {may}, pages = {259{\textendash}270}, abstract = {The Catalan seismic crisis of the years 1427 and 1428 is one of the most destructive seismic episodes that happened in the northeastern Iberian Peninsula in historical times. The main earthquakes of this crisis occurred on March 19th 1427 in the zone around Amer (IEMS-98 = VIII), May 15th 1427 in the vicinity of Olot (IEMS-98 = VIII) and on February 2nd 1428 in the area close to Camprodon (IEMS-98 = IX). There is much evidence that the Amer fault produced the first two events of this crisis, but is still uncertain which fault generated the earthquake on February 2nd 1428. Using newly available macroseismic data, the earthquake area sources of the three main earthquakes of the crisis have been obtained and they corroborate that the Amer fault may be the origin of the first two events. However, the area source corresponding to the last earthquake of the crisis cannot be associated to a single fault and indicates three possible candidates: the Vallfogona and Ribes-Camprodon thrusts and the Amer normal fault. Modeling of the Coulomb failure stress transfer has been performed to help determine the best candidate responsible for the February event. The results of the modeling points to: (a) a triggering relationship between the three main events of the crisis and (b) the Amer fault, or a similar extensional fault close and parallel to it, as the most probable origin of the earthquake on February 2nd 1428. {\textcopyright} 2009 Elsevier Ltd. All rights reserved.}, keywords = {Catalan seismic crisis, Coulomb failure stress transfer, Earthquake triggering, Historical earthquakes, Seismogenic faults}, issn = {02643707}, doi = {10.1016/j.jog.2009.01.002}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-62049083381\&partnerID=tZOtx3y1}, author = {Perea, Hector} } @article {GARCIA2009, title = {{A clustered overlapping sphere algorithm to represent real particles in discrete element modelling}}, journal = {G{\'e}otechnique}, volume = {59}, number = {9}, year = {2009}, month = {jan}, pages = {779{\textendash}784}, abstract = {An algorithm is presented for representing irregular particles as clusters of overlapping spheres, for use within discrete element method (DEM) simulations of particulates. The algorithm is sufficiently fast to be implemented on desktop computers. Although volume and moment of inertia comparisons of resulting clusters with prototypical geometric data show that in the region of 50 to 100 spheres may be needed to represent a particle, actual DEM simulations of an unstable pile of simulated particles show that only 10 or so spheres may be sufficient to capture the mechanics of the system.}, keywords = {Numerical modelling}, issn = {0016-8505}, doi = {10.1680/geot.8.T.037}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77949702642\&partnerID=tZOtx3y1}, author = {Garcia, X. and XIANG, J. and LATHAM, J.-P. and HARRISON, J.P.} } @article {Orejas2009, title = {{Cold-water corals in the Cap de Creus canyon, northwestern Mediterranean: spatial distribution, density and anthropogenic impact}}, journal = {Marine Ecology Progress Series}, volume = {397}, year = {2009}, month = {dec}, pages = {37{\textendash}51}, abstract = {The occurrence and density of 3 cold-water coral (CWC) species (Madrepora oculata, Lophelia pertusa and Dendrophyllia cornigera) were investigated in the Cap de Creus canyon (northwestern Mediterranean) by conducting and analysing 22 video survey transects. Species distribution patterns were also investigated at 3 spatial extents (km, 100s of m and m) across 3 of the transects using spatial statistics. Additionally, the locations of snagged benthic long-line fishing gear were logged across these 3 transects. Video surveys were carried out by both remotely operated vehicles (ROVs) and the JAGO manned submersible. CWCs were present in 15 of the 22 survey transects, predominantly those covering areas with hard substrate (boulders or hardrock outcrops). M. oculata was the most abundant CWC species in the survey transects, whereas L. pertusa and D. cornigera were much more sparsely distributed, with only isolated colonies observed in the majority of transects. M. oculata showed a significant contagious distribution pattern across the analysed transects, with several scales of spatial pattern and patch size being detected, whereas L. pertusa and D. cornigera were not found in sufficient numbers to apply spatial statistics. Different covariance patterns were found across the transects between snagged fishing gear and the presence of M. oculata. Further investigation of this relationship and the level of hazard posed by long-line fishing to M. oculata colonies is required prior to development of a protective management strategy. {\textcopyright} Inter-Research 2009.}, keywords = {Cold water corals, Manned submersible, Patch size, Population density, ROVs, Spatial patterns, Spatial statistic, Submarine canyons}, issn = {0171-8630}, doi = {10.3354/meps08314}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-74049102713\&partnerID=tZOtx3y1}, author = {Orejas, C and Gori, A and Lo Iacono, C and Puig, P and Gili, JM and Dale, MRT} } @article {Latham2009, title = {{Coupled FEMDEM/Fluids for coastal engineers with special reference to armour stability and breakage}}, journal = {Geomechanics and Geoengineering}, volume = {4}, number = {1}, year = {2009}, month = {mar}, pages = {39{\textendash}53}, abstract = {Sea-level rise and increased storminess present huge challenges to coastal engineers worldwide. The seaward slope of many breakwaters and shoreline defence structures consists of thousands of interlocking units of concrete or rock making up a massive granular defence against wave attack. The units are placed freely to form an armour layer which is intended to both dissipate wave energy and remain structurally stable. Design guidance on the mass and shape of these units is based on empirical equations derived from Froude scale physical model tests. The two main failure modes for concrete armour layers are displacement (hydraulic instability) and breakage (structural instability) which are strongly coupled. Breakage mechanisms cannot all be faithfully reproduced under scaled physical models. Fundamental understanding of the forces governing such wave-structure interaction remains poor and unit breakages continue to baffle the designers of concrete armour units. This paper illustrates a range of DEM and FEMDEM methods being developed to model the granular solid skeleton of freely packed brittle units. Such discrete element methods are increasingly being used by engineers for solids modelling. They are especially powerful when coupled with a CFD model which can resolve ocean wave dynamics. The aim is to describe a framework for coupled modelling technologies applicable to coastal engineering problems. Preliminary simulation test cases, still at proof of concept stage, but based on a wealth of validation studies are presented. Thus, we report a snap-shot of progress towards a future where designers combine multi-physics numerical technology with knowledge from scalled physical models for a better understanding of wave energy turbulence, block movement, and internal stresses within armour units.}, keywords = {Breakwaters, Concrete armour units, Discrete element method, Finite element method, Fluid coupling, Ware-structure interaction}, issn = {1748-6025}, doi = {10.1080/17486020902767362}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-68149172944\&partnerID=tZOtx3y1}, author = {Latham, John-Paul and Mindel, Julian and Xiang, Jiansheng and Guises, Romain and Garcia, Xavier and Pain, Chris and Gorman, Gerard and Piggott, Matthew and Munjiza, Antonio} } @article {DelaPuente2009, title = {{Dynamic rupture modeling on unstructured meshes using a discontinuous Galerkin method}}, journal = {Journal of Geophysical Research}, volume = {114}, number = {B10}, year = {2009}, month = {oct}, pages = {B10302}, publisher = {American Geophysical Union}, abstract = {10 pages, 10 figures, 5 tables}, issn = {0148-0227}, doi = {10.1029/2008JB006271}, url = {http://digital.csic.es/handle/10261/83876}, author = {De La Puente, J. and Ampuero, J.-P. and Kaser, M.} } @article {Gutierrez-PastorJ.NelsonC.H.GoldfingerC.JohnsonJ.E.EscutiaC.ErikssonA.T.MoreyA.E.\&ShipboardScientificPartyamongthemGracia2009, title = {{Earthquake Holocene turbidite frequency confirmed by hemipelagic sedimentation on the Cascadia and Northen California active tectonic continental margins}}, journal = {Society for Sedimentary Geology}, year = {2009}, pages = {20}, keywords = {92, C., C.H., Goldfinger, Guti{\'e}rrez-Pastor, J., Nelson, Society for Sedimentary Geology, Sp. Pub.}, isbn = {978-1-56576-136-0.}, url = {http://www.activetectonics.oce.orst.edu/paper\_files/Gutierrez-Pastor et al,2009.pdf}, author = {Gutierrez-Pastor, J. and Nelson, C.H. and Goldfinger, C. and Johnson, J.E. and Escutia, C. and Eriksson, A.T. and Morey, A.E. and Shipboard Scientific Party (among them Gr{\`a}cia, E.)} } @article {Hobbs2009, title = {{Effect of seismic source bandwidth on reflection sections to image water structure}}, journal = {Geophysical Research Letters}, volume = {36}, number = {21}, year = {2009}, month = {nov}, pages = {L00D08}, abstract = {The seismic reflection profile is the convolution of the seismic acquisition impulse response and the target impedance contrasts. In the ocean, these contrasts are mainly determined by the widths and gradients of the temperature transitions between the different water masses. Hence seismic oceanography profiles are sensitive to the frequency bandwidth of the seismic acquisition system. We tested a novel seismic source that allowed us to simultaneously profile the ocean with differing impulse responses. We show that frequencies \~{}20 Hz are best to delineate large impedance contrasts that occur over a vertical scale of several tens of meters whereas frequencies \~{}80 Hz image the boundaries of layers of around 10 m. We demonstrate a towed acquisition system that can operate from a research vessel to give a bandwidth from 10 to 120 Hz that could, if required, be modified to provide frequencies up to 200 Hz. Copyright 2009 by the American Geophysical Union.}, issn = {0094-8276}, doi = {10.1029/2009GL040215}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72049094260\&partnerID=tZOtx3y1}, author = {Hobbs, R. W. and Klaeschen, D. and Sallar{\`e}s, V. and Vsemirnova, E. and Papenberg, C.} } @article {BrumdaSilveira2009, title = {{Evidence for coupled reverse and normal active faulting in W Iberia}}, journal = {Tectonophysics}, volume = {474}, number = {1-2}, year = {2009}, month = {sep}, pages = {184{\textendash}199}, abstract = {The Vidigueira-Moura fault (VMF) is a 65~km long, E-W trending, N dipping reverse left-lateral late Variscan structure located in SE Portugal (W Iberia), which has been reactivated during the Cenozoic with reverse right-lateral slip. It is intersected by, and interferes with the NE-SW trending Alentejo-Plasencia fault. East of this intersection, for a length of 40~km the VMF borders an intracratonic tectonic basin on its northern side, thrusting Paleozoic schists, meta-volcanics and granites, on the north, over Cenozoic continental sediments preserved in the basin, on the south. West of the faults intersection, evidence of Cenozoic reactivation is scarce. In the eastern sector, Plio-Quaternary VMF reactivation is indicated by geomorphologic, stratigraphic, and structural data, showing reverse movement with a right-lateral strike-slip component, in response to a NW-SE trending compressive stress. An average vertical displacement rate of 0.06 to 0.08~mm/yr since late Pliocene (roughly the last 2.5~Ma) is estimated. The Alqueva fault (AF) is a subparallel, northward dipping, 7.5~km long anastomosing fault zone that affects Palaeozoic basement rocks, and is located 2.5~km north and on the hanging block of the VMF. The AF is also a reverse left-lateral late Variscan structure, which has been reactivated during the Tertiary with reverse right-lateral slip; however, Plio-Quaternary reactivation was normal left-lateral, as shown by abundant kinematical criteria (slickensides) and geomorphic evidence. It shows an average displacement rate of 0.02~mm/yr for the vertical component of movement in the approximately last 2.5~Ma. It is proposed that the normal displacements on the AF result from tangential longitudinal strain on the upthrown block of the VMF above a convex ramp of this main reverse structure. According to this model of faults interaction, the AF is interpreted to work as a bending-moment fault sited above the VMF thrust ramp. Consequently, it is expected that the displacements on the AF increase towards the topographic surface with the increase in the imposed extension, declining downwards until they vanish above or at the VMF ramp. In order to constrain the proposed scheme, numerical modeling was performed, aiming at the reproduction of the present topography across the faults using different geodynamic models and fault geometries and displacements. {\textcopyright} 2009 Elsevier B.V. All rights reserved.}, keywords = {Active faulting, Fault interaction, Neotectonics, Numerical modeling, SW Iberia}, issn = {00401951}, doi = {10.1016/j.tecto.2009.04.013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-68849083528\&partnerID=tZOtx3y1}, author = {Brum da Silveira, A. and Cabral, J. and Perea, H. and Ribeiro, A.} } @article {Petersen2009, title = {{Fluid seepage and mound formation offshore Costa Rica revealed by deep-towed sidescan sonar and sub-bottom profiler data}}, journal = {Marine Geology}, volume = {266}, number = {1-4}, year = {2009}, month = {oct}, pages = {172{\textendash}181}, abstract = {Our analysis of geoacoustic data from the Middle American margin provides an insight into the formation and evolution mechanisms of mound structures observed on the continental slope offshore Costa Rica. Based on high-resolution deep-towed sidescan sonar and sub-bottom profiler (SBP) data six different mound and fluid seepage structures at the Hongo mound field are characterized in detail. The Hongo mound field is located on the lower continental slope offshore Nicoya peninsula in the prolongation of the subducting Nicoya fracture zone. The mounds have oval to circular shapes with diameters of 500-1600 m and relief heights of 60-100 m. High backscatter anomalies near the mound summits indicate carbonate precipitation and focused fluid seepage activity within the last 10 ka. The data do not show evidence for mud extrusions and the structures were probably formed by a combination of carbonate precipitation and mud diapirism. Based on seismic stratigraphy analysis, mud diapirism is at least active since 42.5-57 ka and average vertical growth rates vary between 6-24 cm/ka. However, if diapirism represents the dominant mound evolution mechanism, mound heights of 80 m point to much older mound ages of 330-1330 ka. {\textcopyright} 2009 Elsevier B.V. All rights reserved.}, keywords = {carbonate, deep-towed side-scan sonar, fluid seepage, mound, mud diapir, sub-bottom profiler}, issn = {00253227}, doi = {10.1016/j.margeo.2009.08.004}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72049084256\&partnerID=tZOtx3y1}, author = {Petersen, Carl J{\"o}rg and Klaucke, Ingo and Weinrebe, Wilhelm and Ranero, Cesar R.} } @article {Yang2009, title = {{Geotechnical Properties of River-fed Sediments Compared with Glacier-fed Sediments}}, journal = {Marine Georesources \& Geotechnology}, volume = {27}, number = {4}, year = {2009}, month = {oct}, pages = {281{\textendash}295}, abstract = {This paper discusses the influence of sedimentary environment and geological setting on geotechnical and physical properties of resulting sedimentary deposits. For this study, two different geological settings were considered, one is a river-fed and the other is a glacier-fed sedimentary environment. For both sedimentary environments, various geotechnical properties were considered and compared. These include plasticity, activity, compressibility, undrained shear strength and sensitivity. Results indicate that physical and geotechnical properties of sediments deposited in these two settings are significantly different. These differences are then interpreted in terms of the various mechanisms involved in submarine slope failure initiation in river-fed versus glacier-fed sedimentary environments. {\textcopyright} Taylor \& Francis Group, LLC.}, keywords = {Activity, Compressibility, Plasticity, Sedimentary environment, Sensitivity, Shear strength, Submarine landslides}, issn = {1064-119X}, doi = {10.1080/10641190903025214}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70449408082\&partnerID=tZOtx3y1}, author = {Yang, S. L. and Solheim, A. and Forsberg, C. F. and Kvalstad, T. and Feng, X. L. and Li, A. L. and Urgeles, R.} } @article {Buske2009, title = {{Imaging and inversion {\textemdash} Introduction}}, journal = {GEOPHYSICS}, volume = {74}, number = {6}, year = {2009}, month = {nov}, pages = {WCA1{\textendash}WCA4}, issn = {0016-8033}, doi = {10.1190/1.3256872}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861190134\&partnerID=tZOtx3y1}, author = {Buske, Stefan and Lecomte, Isabelle and Nemeth, Tamas and Operto, St{\'e}phane and Sallares, Valenti} } @article {Muller2009, title = {{Lithospheric structure, evolution and diamond prospectivity of the Rehoboth Terrane and western Kaapvaal Craton, southern Africa: Constraints from broadband magnetotellurics}}, journal = {Lithos}, volume = {112}, year = {2009}, month = {nov}, pages = {93{\textendash}105}, abstract = {A 1400~km-long, 2-D magnetotelluric (MT) profile, consisting of 69 sites at 20~km intervals, across the western part of the Archaean Kaapvaal Craton, the Proterozoic Rehoboth Terrane and the Late Proterozoic/Early Phanerozoic Ghanzi-Chobe/Damara Belt reveals significant lateral heterogeneity in the electrical resistivity structure of the southern African lithosphere. The lithospheric structures of the Rehoboth Terrane and Ghanzi-Chobe/Damara Belt have not been imaged previously by geophysical methods. Temperature is the primary control on the resistivity of mantle minerals, and the MT derived lithospheric thicknesses therefore provide a very reasonable proxy for the "thermal" thickness of the lithosphere (i.e., the thickness defined by the intersection of a conductive geotherm with the mantle adiabat), allowing approximate present-day geotherms to be calculated. The work indicates the following present-day average lithospheric thicknesses, to a precision of about {\textpm} 20~km, for each of the terranes traversed (inferred geotherms in brackets): Eastern Kimberley Block of the Kaapvaal Craton 220~km (41~mW m- 2), Western Kimberley Block 190~km (44~mW m- 2), Rehoboth Terrane 180~km (45~mW m- 2) and Ghanzi-Chobe/Damara Belt 160~km (48~mW m- 2). A clear relationship between the electrical resistivity structure of the lithosphere and the tectonic stabilisation-age of the terrane is evident. Good agreement between the inferred present-day lithospheric geotherms and surface heat flow measurements indicate the latter are strongly controlled by variations in lithospheric thickness. A significant difference in lithospheric thickness is observed between the Eastern and Western Kimberley blocks, and is consistent with previous seismic tomography images of the Kaapvaal Craton. The present-day lithospheric thickness, and reduced depth extent into the diamond stability field, accounts for the absence of diamondiferous kimberlites in the Gibeon and Gordonia kimberlite fields in the Rehoboth Terrane. Previously published mantle xenolith P-T arrays from the Gibeon, Gordonia and Kimberley fields, however, suggest that the Rehoboth Terrane had equilibrated to a cooler conductive palaeo-geotherm (40-42~mW m- 2 ), very similar to that of Eastern Kimberley Block of the Kaapvaal Craton, at some time prior to the Mesozoic eruption of the kimberlites. The timing and nature of both the thermal equilibration of the Rehoboth Terrane, and the subsequent lithospheric heating/thinning event required to account for its present-day lithospheric structure, are not well constrained. A model consisting of the penetration of heat transporting magmas into the lithosphere, with associated chemical refertilisation, at an early stage of Mesozoic thermalism appears to be the most plausible model at present to account for both the present-day lithospheric structure of the Rehoboth Terrane and an earlier, cooler palaeo-geotherm. Some problems, however, remain unresolved in terms of the isostatic response of the model. Based on a compilation of xenocryst Cr/Ca-in-pyrope barometry observations, the extent of depleted mantle in the Rehoboth Terrane is found to be significantly reduced with respect to the Eastern Kimberley Block: 117~km versus 138-167~km. It appears most likely that the depletion depth in both terranes, at least in the vicinity of kimberlite eruption, is explained by refertilisation of the lower lithospheric mantle. {\textcopyright} 2009.}, keywords = {Diamond, Geotherm, Lithosphere, Magnetotellurics, Southern Africa, Xenolith}, issn = {00244937}, doi = {10.1016/j.lithos.2009.06.023}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72049130282\&partnerID=tZOtx3y1}, author = {Muller, M.R. and Jones, A.G. and Evans, R.L. and Gr{\"u}tter, H.S. and Hatton, C. and Garcia, X. and Hamilton, M.P. and Miensopust, M.P. and Cole, P. and Ngwisanyi, T. and Hutchins, D. and Fourie, C.J. and Jelsma, H.A. and Evans, S.F. and Aravanis, T. and Pettit, W. and Webb, S.J. and Wasborg, J.} } @article {Kormann2009, title = {{Modelling Seismic Oceanography Experiments by Using First- and Second-Order Complex Frequency Shifted Perfectly Matched Layers}}, journal = {Acta Acustica united with Acustica}, volume = {95}, number = {6}, year = {2009}, month = {nov}, pages = {1104{\textendash}1111}, abstract = {This work investigates the ability of modelling seismic oceanography experiments by using underwater acoustic propagation equations. Seismic oceanography tries to retrieve the fine structure of the ocean water masses by processing the acoustic waves reflected in the low-contrast interfaces of fronts, eddies, internal waves or thermohaline intrusions. Since the reflectivity of such interfaces is of order 10-3-10-4, the absorption capability of the numerical boundaries becomes crucial. Complex Frequency Shifted offers a better alternative to classical Perfectly Matched Layer formulation, but has not yet been extended to acoustic equations. Here, first- and second-order Complex Frequency Shifted Perfectly Matched Layers equations are proposed which can provide reflection coefficients of order 10-5. Therefore, a numerical Finite-Difference Time-Domain (FDTD) scheme combined with the proposed CFS-PML equations is able to model such experiments. {\textcopyright} S. Hirzel Verlag {\textperiodcentered} EAA.}, issn = {16101928}, doi = {10.3813/AAA.918242}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77149123321\&partnerID=tZOtx3y1}, author = {Kormann, Jean and Cobo, Pedro and Recuero, Manuel and Biescas, Berta and Sallares, Valenti} } @article {Bartolome2009, title = {{Multiscale seismic imaging of active faults at sea}}, journal = {Sea Technology}, volume = {50}, number = {2}, year = {2009}, pages = {10{\textendash}14}, issn = {00933651}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-62749191283\&partnerID=tZOtx3y1}, author = {Bartolom{\'e}, Rafael and Iacono, Claudio Lo and Gr{\'a}cia, Eul{\`a}lia} } @article {Palomeras2009, title = {{Nature of the lithosphere across the Variscan orogen of SW Iberia: Dense wide-angle seismic reflection data}}, journal = {Journal of Geophysical Research}, volume = {114}, number = {B2}, year = {2009}, month = {feb}, pages = {B02302}, abstract = {Two wide-angle seismic transects have been acquired across the SW Iberian Massif. They crossed three major geological zones (South Portuguese Zone, Ossa-Morena Zone, and Central Iberian Zone), with their tectonic contacts and the Pyrite Belt being of greatest interest. A total of 690 digital seismic recording instruments (650 Texans and 40 Reftek 3 component units) from the IRIS-PASSCAL Instrument Pool were used. The transects (A and B) are each approximately 300 km long and consist of 3 and 6 shot points, respectively, with an approximately 60-km shot point interval. The charge sizes range from 1000 kg at the edges to 500 kg at the center. These recently acquired experiments were designed to provide velocity constraints on the lithosphere and to complement the previously acquired normal incidence seismic profile IBERSEIS. Both data sets are part of the SW Iberia project, which was developed within the EUROPROBE program and designed to address fundamental questions about the nature and dynamics of the Variscan lithosphere. The acquisition parameters provide closely spaced wide-angle seismic images of the lithosphere beneath SW Iberia. In transect A, the station spacing was on average 400 m, while along transect B, the receiver spacing was approximately 150 m. Because of this close trace spacing, the lateral continuity of the seismic arrivals is greatly improved. Frequency analysis revealed that the recorded events feature relatively low frequencies (6-25 Hz). After processing, the shot records show high-amplitude and well-defined arrivals. The interpreted PmP arrival, located at approximately 11 s (normal incidence traveltime), is characterized by high amplitude and relatively low frequency (6-12 Hz). A well-defined Pn arrival appears at offsets beyond 120 km. At far offsets greater than 180 km, an upper mantle reflection is observed. Furthermore, within the upper crust, the shots records feature a relatively high-velocity arrival, located at 4-5-s normal incidence traveltime. The analysis of this arrival indicates that it probably corresponds to the top of the Iberian Reflective Body identified in the IBERSEIS deep seismic profile. The velocity models obtained by forward modeling show a complex crust, especially in the middle crust. The velocity models are the most detailed ones that have been produced in the area and contain a large amount of new features that are relevant to the understanding of the composition of the crust and upper mantle beneath the zone. The velocity depth functions derived from the velocity models have higher middle crustal velocities than the average in other continental areas. A comparison between laboratory seismic velocity measurements and the velocities of the models was carried out in order to estimate the crustal and the upper mantle composition. Results indicate that the high middle crust velocities correspond to rocks of a mafic composition. The combined data set reveals new aspects related to the lithospheric evolution of this transpressive orogen and allows us to attempt an interpretative cross section of the upper lithosphere in SW Iberia. {\textcopyright} 2009.}, issn = {0148-0227}, doi = {10.1029/2007JB005050}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-66149180585\&partnerID=tZOtx3y1}, author = {Palomeras, I. and Carbonell, R. and Flecha, I. and Simancas, F. and Ayarza, P. and Matas, J. and Mart{\'\i}nez Poyatos, D. and Azor, A. and Gonz{\'a}lez Lodeiro, F. and P{\'e}rez-Esta{\'u}n, A.} } @article {VonHuene2009, title = {{Neogene collision and deformation of convergent margins along the backbone of the Americas}}, journal = {Geological Society of America Memoirs}, volume = {204}, year = {2009}, month = {jun}, pages = {67{\textendash}83}, abstract = {Along Pacific convergent margins of the Americas, high-standing relief on the subducting oceanic plate "collides" with continental slopes and subducts. Features common to many collisions are uplift of the continental margin, accelerated seafloor erosion, accelerated basal subduction erosion, a flat slab, and a lack of active volcanism. Each collision along America{\textquoteright}s margins has exceptions to a single explanation. Subduction of an \~{}600 km segment of the Yakutat terrane is associated with >5000-m-high coastal mountains. The terrane may currently be adding its unsubducted mass to the continent by a seaward jump of the deformation front and could be a model for docking of terranes in the past. Cocos Ridge subduction is associated with >3000-m-high mountains, but its shallow subduction zone is not followed by a flat slab. The entry point of the Nazca and Juan Fernandez Ridges into the subduction zone has migrated southward along the South American margin and the adjacent coast without unusually high mountains. The Nazca Ridge and Juan Fernandez Ridges are not actively spreading but the Chile Rise collision is a triple junction. These collisions form barriers to trench sediment transport and separate accreting from eroding segments of the frontal prism. They also occur at the separation of a flat slab from a steeply dipping one. At a smaller scale, the subduction of seamounts and lesser ridges causes temporary surface uplift as long as they remain attached to the subducting plate. Off Costa Rica, these features remain attached beneath the continental shelf. They illustrate, at a small scale, the processes of collision. {\textcopyright} 2009 The Geological Society of America. All rights reserved.}, issn = {0072-1069}, doi = {10.1130/2009.1204(03)}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77949859751\&partnerID=tZOtx3y1}, author = {von Huene, R and Ranero, C.R} } @article {Garcia2009, title = {{Numerical study of the effects of particle shape and polydispersity on permeability}}, journal = {Physical Review E}, volume = {80}, number = {2}, year = {2009}, month = {aug}, pages = {021304}, abstract = {We study through numerical simulations the dependence of the hydraulic permeability of granular materials on the particle shape and the grain size distribution. Several models of sand are constructed by simulating the settling under gravity of the grains; the friction coefficient is varied to construct packs of different porosity. The size distribution and shapes of the grains mimic real sands. Fluid flow is simulated in the resulting packs using a finite element method and the permeability of the packs is successfully compared with available experimental data. Packs of nonspherical particles are less permeable than sphere packs of the same porosity. Our results indicate that the details of grain shape and size distribution have only a small effect on the permeabilty of the systems studied. {\textcopyright} 2009 The American Physical Society.}, issn = {1539-3755}, doi = {10.1103/PhysRevE.80.021304}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349241904\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Akanji, Lateef and Blunt, Martin and Matthai, Stephan and Latham, John} } @article {Pham2009, title = {{Observations and Modeling of Rotational Signals in the P Coda: Constraints on Crustal Scattering}}, journal = {Bulletin of the Seismological Society of America}, volume = {99}, number = {2B}, year = {2009}, month = {may}, pages = {1315{\textendash}1332}, abstract = {In addition to three classical components (vertical, north-south, and east-west) of ground translations recorded by a broadband seismometer, a component of earthquake induced rotational ground motions around the vertical axis is consistently measured by a ring laser sensor located in Wettzell, southeast Germany. Significant rotations around the vertical axis in the P coda of teleseismic signals are either directly visible or can be inferred through the investigation of cross correlation between the transverse component (the component that is perpendicular to the great circle connecting the earthquake and the seismometer) of translation acceleration and ring laser rotation rate. Theoretically, in spherically symmetric isotropic media, we should not observe rotational signals around the vertical axis before the onset of SH waves. Possible causes for the observed rotations in the P coda are: (1) tilt-ring laser coupling, (2) anisotropy, (3) topographic scattering, and (4) P-SH scattering in the crust. Here we show that P-SH scattering in the 3D random crust can explain the observations and allow us to constrain crustal scattering properties.}, issn = {0037-1106}, doi = {10.1785/0120080101}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67649949683\&partnerID=tZOtx3y1}, author = {Pham, N. D. and Igel, H. and Wassermann, J. and Kaser, M. and De La Puente, J. and Schreiber, U.} } @booklet {MorenoMota2009, title = {{Paleoseismology of active faults based on multiscale seismic imaging}}, journal = {Instrumentation ViewPoint}, number = {8}, year = {2009}, pages = {50{\textendash}51}, publisher = {Universitat Polit{\`e}cnica de Catalunya}, abstract = {The study of active structures offshore requires very-high resolution seismic imaging in order to observe the most recent layers below sea floor. In the other hand, high penetration methods are necessary to observe deeper reflections for understanding the evolution of the structure throughout the time. The aim of our study is to establish the seismic potential of the offshore segment of the Carboneras Fault, Eastern Betics, based on multiscale seismic imaging. Three different scale methods have been acquired and are compared here: very-high-resolution sub-bottom profiler TOPAS, very-high-resolution single-channel seismic (Sparker) and high-resolution multi-channel seismic. From seismic profiles, faulted Quaternary layers suggest that the Carboneras Fault is active. Sediment coring and dating analysis are used to consider ages for key reflectors observed in TOPAS profiles, and a change in the vertical slip-rate through the Quaternary is inferred.}, keywords = {Tecnolog{\'\i}a industrial. Tecnolog{\'\i}a mec{\'a}nica, Tecnolog{\'\i}as}, issn = {1886-4864}, url = {http://dialnet.unirioja.es/servlet/articulo?codigo=3202510\&info=resumen\&idioma=ENG}, author = {Moreno Mota, Ximena and Gr{\`a}cia i Mont, Eulalia and Bartolom{\'e}, Rafael and Iacono, Claudio} } @article {Zitellini2009, title = {{The quest for the Africa{\textendash}Eurasia plate boundary west of the Strait of Gibraltar}}, journal = {Earth and Planetary Science Letters}, volume = {280}, number = {1-4}, year = {2009}, month = {apr}, pages = {13{\textendash}50}, abstract = {The missing link in the plate boundary between Eurasia and Africa in the central Atlantic is presented and discussed. A set of almost linear and sub parallel dextral strike-slip faults, the SWIM11SWIM is the acronym of the ESF EuroMargins project "Earthquake and Tsunami hazards of active faults at the South West Iberian Margin: deep structure, high-resolution imaging and paleoseismic signature". Faults, that form a narrow band of deformation over a length of 600~km coincident with a small circle centred on the pole of rotation of Africa with respect to Eurasia, was mapped using a new swath bathymetry compilation available in the area offshore SW Portugal. These faults connect the Gloria Fault to the Rif-Tell Fault Zone, two segments of the plate boundary between Africa and Eurasia. The SWIM faults cut across the Gulf of Cadiz, in the Atlantic Ocean, where the 1755 Great Lisbon earthquake, M \~{} 8.5-8.7, and tsunami were generated, providing a new insight on its source location. {\textcopyright} 2008 Elsevier B.V. All rights reserved.}, keywords = {Africa-Eurasia plate boundary, Great Lisbon Earthquake, Gulf of Cadiz, Iberia, Nubia}, issn = {0012821X}, doi = {10.1016/j.epsl.2008.12.005}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-62749129333\&partnerID=tZOtx3y1}, author = {Zitellini, N. and Gr{\`a}cia, E. and Matias, L. and Terrinha, P. and Abreu, M.A. and DeAlteriis, G. and Henriet, J.P. and Da{\~n}obeitia, J.J. and Masson, D.G. and Mulder, T.} } @article {Sallares2009, title = {{Relative contribution of temperature and salinity to ocean acoustic reflectivity}}, journal = {Geophysical Research Letters}, volume = {36}, number = {20}, year = {2009}, month = {oct}, pages = {L00D06}, abstract = {Marine seismic data display laterally coherent reflectivity from the water column that is attributed to fine-scale oceanic layering. The amplitude of the different reflections is the expression of acoustic impedance contrasts. between neighbouring water masses, and therefore water reflectivity maps the ocean{\textquoteright}s vertical sound speed and density (i.e., temperature and salinity) variations. Here we determine the relative contribution of each parameter by computing the temperature and salinity partial derivatives of sound speed and density, and using them to estimate reflection coefficients from a real oceanographic dataset. The results show that the mean contribution of density variations is 5-10\%, while 90-95\% is due to sound speed variations. On average, 80\% of reflectivity comes from temperature contrasts. Salinity contribution averages 20\%, but it is highly variable and reaches up to 40\% in regions prone to diffusive convection such as the top of the Mediterranean Undercurrent in the Gulf of Cadiz. Copyright 2009 by the American Geophysical Union.}, issn = {0094-8276}, doi = {10.1029/2009GL040187}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72149084920\&partnerID=tZOtx3y1}, author = {Sallar{\`e}s, V. and Biescas, B. and Buffett, G. and Carbonell, R. and Danobeitia, J. J. and Pelegr{\'\i}, J. L.} } @article {Lebreiro2009, title = {{Sediment instability on the Portuguese continental margin under abrupt glacial climate changes (last 60kyr)}}, journal = {Quaternary Science Reviews}, volume = {28}, number = {27-28}, year = {2009}, month = {dec}, pages = {3211{\textendash}3223}, abstract = {It is well established that orbital scale sea-level changes generated larger transport of sediments into the deep-sea during the last glacial maximum than the Holocene. However, the response of sedimentary processes to abrupt millennial-scale climate variability is rather unknown. Frequency of distal turbidites and amounts of advected detrital carbonate are estimated off the Lisbon-Set{\'u}bal canyons (core MD03-2698, at 4602 mwd), within a chronostratigraphy based on radiometric ages, oxygen isotopes and paleomagnetic key global anomalies. We found that: 1) higher frequency of turbidites concurred with Northern Hemisphere coldest temperatures (Greenland Stadials [GS], including Heinrich [H] events). But more than that, an escalating frequency of turbidites starts with the onset of global sea-level rising (and warming in Antarctica) and culminates during H events, at the time when rising is still in its early-mid stage, and the Atlantic Meridional Overturning Circulation (AMOC) is re-starting. This short time span coincides with maximum gradients of ocean surface and bottom temperatures between GS and Antarctic warmings (Antarctic Isotope Maximum; AIM 17, 14, 12, 8, 4, 2) and rapid sea-level rises. 2) Trigger of turbidity currents is not the only sedimentary process responding to millennial variability; land-detrital carbonate (with a very negative bulk $δ$18O signature) enters the deep-sea by density-driven slope lateral advection, accordingly during GS. 3) Possible mechanisms to create slope instability on the Portuguese continental margin are sea-level variations as small as 20 m, and slope friction by rapid deep and intermediate re-accommodation of water masses circulation. 4) Common forcing mechanisms appear to drive slope instability at both millennial and orbital scales. {\textcopyright} 2009.}, issn = {02773791}, doi = {10.1016/j.quascirev.2009.08.007}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70549094210\&partnerID=tZOtx3y1}, author = {Lebreiro, S.M. and Voelker, A.H.L. and Vizcaino, A. and Abrantes, F.G. and Alt-Epping, U. and Jung, S. and Thouveny, N. and Gr{\`a}cia, E.} } @conference {Urgeles2009, title = {{Sediment undulations on the Llobregat prodelta: Signs of early slope instability or sedimentary bedforms?}}, booktitle = {Rendiconti Online Societa Geologica Italiana}, volume = {7}, year = {2009}, pages = {103{\textendash}106}, abstract = {A field of sediment undulations has been mapped in the Llobregat River prodelta. similar features had been recognized in other prodeltas and interpreted either as deformation or sedimentary structures. therefore, proper interpretation of these undulations is needed for correct risk assessment. We evaluate the characteristics of the sediment undulations in order to determine the most likely process for the origin of these structures. these characteristics indicate that the sediment undulations on the Llobregat River prodelta do not result from sediment deformation. their identification as sediment waves implies that such features do not pose a major hazard for further offshore development.}, issn = {20358008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84863328164\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and De Mol, Ben and Puig, Pere and De Batist, Marc and Hughes-Clarke, John E.} } @article {Flecha2009, title = {{Seismic imaging and modelling of the lithosphere of SW-Iberia}}, journal = {Tectonophysics}, volume = {472}, number = {1-4}, year = {2009}, month = {jul}, pages = {148{\textendash}157}, abstract = {Data from a closely spaced wide-angle transect has been used to study the middle-to-lower crust and the Moho in SW-Iberia. A low-fold wide-angle stack image reveals a highly heterogeneous seismic signature at lower-crustal levels changing laterally along the profile. The lower crust features an irregular distribution of the reflectivity that can be explained by a heterogeneous distribution of physical properties. The Moho discontinuity also features a high variability in its seismic character that correlates with the different tectonic terranes in the area. A 2D finite difference code was used for solving the elastic wave equation and to provide synthetic wide-angle shots. Relatively simple layer cake model derived from conventional refraction interpretation generates the main events of the shot records. However, these models cannot account for the lateral variability of the seismic signature. In order to obtain more realistic simulations, the velocity model was modified introducing stochastic lensing at different levels within the crust. The Moho was modelled as a 3~km thick layered structure. The resulting average velocity models include a high velocity layer at mid-crustal depth, a highly reflective lower crust and a relatively thin horizontal Moho. This heterogeneous model can be achieved by lensing within the crust, a layered mafic intrusion and a strongly laminated lower crust and Moho. {\textcopyright} 2008 Elsevier B.V. All rights reserved.}, keywords = {Crustal heterogeneities, Mafic intrusions, Wide-angle stack}, issn = {00401951}, doi = {10.1016/j.tecto.2008.05.033}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67349173557\&partnerID=tZOtx3y1}, author = {Flecha, I. and Palomeras, I. and Carbonell, R. and Simancas, F. and Ayarza, P. and Matas, J. and Gonz{\'a}lez-Lodeiro, F. and P{\'e}rez-Esta{\'u}n, A.} } @article {Buffett2009, title = {{Seismic reflection along the path of the Mediterranean Undercurrent}}, journal = {Continental Shelf Research}, volume = {29}, number = {15}, year = {2009}, month = {aug}, pages = {1848{\textendash}1860}, abstract = {Seismic reflection profiling is applied to the study of large scale physical oceanographic processes in the Gulf of C{\'a}diz and western Iberian coast, coinciding with the path of the Mediterranean Undercurrent. The multi-channel seismic reflection method provides clear images of thermohaline fine structure with a horizontal resolution approximately two orders of magnitude higher than CTD casting. The seismic data are compared with co-located historical oceanographic data. Three seismic reflectivity zones are identified: North Atlantic Central Water, Mediterranean Water and North Atlantic Deep Water. Seismic evidence for the path of the Mediterranean Undercurrent is found in the near-slope reflectivity patterns, with rising reflectors between about 500 and 1500 m. However, the core of the undercurrent is largely transparent. Seismic images show that central and, particularly, intermediate Mediterranean Waters have fine structure coherent over horizontal distances of several tens of kilometers. However, the intensity of the reflectors, and their horizontal coherence, decreases downstream. This change in seismic reflectivity is probably the result of diminished vertical thermohaline contrasts between adjacent water masses, so that double-diffusion processes become unable to sustain temperature and salinity staircases. Comparison of root-mean-square seismic amplitudes with temperature and salinity differences between the Mediterranean Undercurrent and the overlying central waters suggests a causal relationship between observed thermohaline fine structure and true seismic amplitudes. We estimate that, within this intermediate water stratum, impedance contrasts are mainly controlled by sound speed contrasts (a factor between 3.5 and 10 times larger than density contrasts), which are mainly controlled by temperature contrasts (a factor between 1.5 and 5 times larger than salinity contrasts). {\textcopyright} 2009 Elsevier Ltd. All rights reserved.}, keywords = {Amplitude, Entrainment, Mediterranean Undercurrent, Mixing, Salinity, Seismic oceanography, Temperature, thermohaline fine structure}, issn = {02784343}, doi = {10.1016/j.csr.2009.05.017}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-69249209739\&partnerID=tZOtx3y1}, author = {Buffett, G.G. and Biescas, B. and Pelegr{\'\i}, J.L. and Mach{\'\i}n, F. and Sallar{\`e}s, V. and Carbonell, R. and Klaeschen, D. and Hobbs, R.} } @conference {Monteys2009, title = {{Shallow geophysical characterization and fluid flow processes in two large pockmarks on the Malin Shelf, NW Ireland}}, booktitle = {Near Surface 2009 - 15th European Meeting of Environmental and Engineering Geophysics}, year = {2009}, publisher = {European Association of Geoscientists and Engineers, EAGE}, organization = {European Association of Geoscientists and Engineers, EAGE}, abstract = {Shallow geophysical datasets and ground-truthing have been used in this research to characterize in detail two large gas related depressions in a recently discovered pockmark field on the Malin Shelf, northwest Ireland. Pockmarks are aligned to the main deep fault of the region, the SW-NE Skerryvore Fault. High resolution multibeam bathymetry and backscatter reveal the surface morphology of these seabed features to the meter scale. They appear as subcircular depressions and present several units within a generally smooth seabed. Shallow seismic and single-beam echosounder records reveal evidence of gas related activity within the subsurface strata. Electromagnetic results present a number of anomalies in conductivity associated with inhomogenities in the upper strata. These anomalies consist in a decrease in conductivity and in general, correlate well with acoustic anomalies.}, isbn = {9073781728}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84912149526\&partnerID=tZOtx3y1}, author = {Monteys, X. and Garcia, X. and Evans, R. and Szpak, M. and Kelleher, B. and Hardy, D.} } @article {Stupazzini2009, title = {{Study of Rotational Ground Motion in the Near-Field Region}}, journal = {Bulletin of the Seismological Society of America}, volume = {99}, number = {2B}, year = {2009}, month = {may}, pages = {1271{\textendash}1286}, abstract = {During the nineteenth and twentieth centuries observational seismologists recorded primarily the earthquake-induced translational wave field, while the rotational motion still remains poorly observed and investigated. We aim to further understand the rotational ground motion and its relation to the translational wave field, with a special emphasis on the near field, a few wavelengths away from the hypocenter, where damage related to rotational motion might need to be considered. A broad picture of the available values of rotational amplitudes and their variability is obtained by gathering most of the published data on strong rotational motion. To obtain a more detailed picture we perform a large scale 3D numerical study of a strike-slip event in the Grenoble valley where a combination of topographic, source, and site effects produces a realistic wave field. We analyzed the synthetic dataset in terms of the rotational and translational peak amplitudes and their dependence on two effects: nonlinear soil behavior and source directivity. On a soft soil deposit, we observe peak ground rotation of 1 mrad and the peak ground rotation rate of 10 mrad/sec, for an Mw 6.0 event. Those values show a strong dependence on the hypocenter location, the local site conditions, and the topographical features, inducing a variability of almost one order of magnitude in a range of distances of 20 km. Finally, we compare our numerical results in terms of peak ground velocity (PGV) versus peak ground rotation (PG${\o}mega$) with field data obtained at similar scenarios (e.g., Parkfield) by array techniques to investigate the relation between translational and rotational amplitudes expected in the near field for shallow, medium-sized earthquakes. Results of our numerical simulation fit reasonably well with those observed in past studies. Furthermore, the spatial variations of the PGV/PG${\o}mega$ ratio show a trend, which is correlated with the velocity structure of the model under study.}, issn = {0037-1106}, doi = {10.1785/0120080153}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67649962349\&partnerID=tZOtx3y1}, author = {Stupazzini, M. and De La Puente, J. and Smerzini, C. and Kaser, M. and Igel, H. and Castellani, A.} } @book {VonHuene2009a, title = {{Subduction Zone Geodynamics}}, series = {Frontiers in Earth Sciences}, year = {2009}, month = {oct}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, abstract = {21 pages, 8 figures, 1 table}, keywords = {Accretion, Convergent margins, Subduction erosion}, isbn = {978-3-540-87971-8}, doi = {10.1007/978-3-540-87974-9}, url = {http://digital.csic.es/handle/10261/83778 http://hdl.handle.net/10261/83778}, author = {von Huene, Roland and Ranero, Cesar R. and Scholl, Dave W.}, editor = {Lallemand, Serge and Funiciello, Francesca} } @article {Simancas2009, title = {{Tectonic relationships of Southwest Iberia with the allochthons of Northwest Iberia and the Moroccan Variscides}}, journal = {Comptes Rendus Geoscience}, volume = {341}, number = {2-3}, year = {2009}, month = {feb}, pages = {103{\textendash}113}, abstract = {The Iberian Massif poses a problem of relationships between its northwestern and southern parts. Suture terranes (ophiolites and high-pressure rocks) crop out in NW Iberia but only as allochthonous units, unconnected from their root zone. Sutures cropping out in SW Iberia are discussed in order to relate them to the unknown root of the NW Iberia allochthons. On the other hand, the Moroccan Variscides are very briefly presented with a view to propose their correlation with the Iberian zones. Particularly important is the transition from the Variscides to the Paleoproterozoic basement in Morocco, which is a key argument for palaeogeographic reconstructions. {\textcopyright} 2008 Acad{\'e}mie des sciences.}, keywords = {Correlations, Iberia, Morocco, Sutures, Variscan orogen}, issn = {16310713}, doi = {10.1016/j.crte.2008.11.003}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-63049089339\&partnerID=tZOtx3y1}, author = {Simancas, Jos{\'e} Fernando and Azor, Antonio and Mart{\'\i}nez-Poyatos, David and Tahiri, Abdelfatah and El Hadi, Hassan and Gonz{\'a}lez-Lodeiro, Francisco and P{\'e}rez-Esta{\'u}n, Andr{\'e}s and Carbonell, Ram{\'o}n} } @article {Gutscher2009, title = {{Tectonic shortening and gravitational spreading in the Gulf of Cadiz accretionary wedge: Observations from multi-beam bathymetry and seismic profiling}}, journal = {Marine and Petroleum Geology}, volume = {26}, number = {5}, year = {2009}, month = {may}, pages = {647{\textendash}659}, abstract = {The Gulf of Cadiz lies astride the complex plate boundary between Africa and Eurasia west of the Betic-Rif mountain belt. We report on the results of recent bathymetric swathmapping and multi-channel seismic surveys carried out here. The seafloor is marked by contrasting morphological provinces, spanning the SW Iberian and NW Moroccan continental margins, abyssal plains and an elongate, arcuate, accretionary wedge. A wide variety of tectonic and gravitational processes appear to have shaped these structures. Active compressional deformation of the wedge is suggested by folding and thrusting of the frontal sedimentary layers as well as basal duplexing in deeper internal units. There is evidence for simultaneous gravitational spreading occurring upslope. The very shallow mean surface and basal slopes of the accretionary wedge (1{\textdegree} each) indicate a very weak decollement layer, geometrically similar to the Mediterranean Ridge accretionary complex. Locally steep slopes (up to 10{\textdegree}) indicate strongly focused, active deformation and potential gravitational instabilities. The unusual surface morphology of the upper accretionary wedge includes "raft-tectonics" type fissures and abundant sub-circular depressions. Dissolution and/or diapiric processes are proposed to be involved in the formation of these depressions. {\textcopyright} 2008 Elsevier Ltd. All rights reserved.}, keywords = {Accretionary wedge, Decollement, Gravitational spreading, Iberia, Morocco}, issn = {02648172}, doi = {10.1016/j.marpetgeo.2007.11.008}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67349128699\&partnerID=tZOtx3y1}, author = {Gutscher, Marc-Andr{\'e} and Dominguez, Stephane and Westbrook, Graham K. and Gente, Pascal and Babonneau, Nathalie and Mulder, Thierry and Gonthier, Eliane and Bartolom{\'e}, Rafael and Luis, Joaquim and Rosas, Filipe and Terrinha, Pedro} } @article {MonteiroSantos2009, title = {{Using tensorial electrical resistivity survey to locate fault systems}}, journal = {Journal of Geophysics and Engineering}, volume = {6}, number = {4}, year = {2009}, month = {dec}, pages = {390{\textendash}400}, abstract = {This paper deals with the use of the tensorial resistivity method for fault orientation and macroanisotropy characterization. The rotational properties of the apparent resistivity tensor are presented using 3D synthetic models representing structures with a dominant direction of low resistivity and vertical discontinuities. It is demonstrated that polar diagrams of the elements of the tensor are effective in delineating those structures. As the apparent resistivity tensor shows great inefficacy in investigating the depth of the structures, it is advised to accomplish tensorial surveys with the application of other geophysical methods. An experimental example, including tensorial, dipole-dipole and time domain surveys, is presented to illustrate the potentiality of the method. The dipole-dipole model shows high-resistivity contrasts which were interpreted as corresponding to faults crossing the area. The results from the time domain electromagnetic (TEM) sounding show high-resistivity values till depths of 40-60 m at the north part of the area. In the southern part of the survey area the soundings show an upper layer with low-resistivity values (around 30 ${\O}mega$ m) followed by a more resistive bedrock (resistivity >100 ${\O}mega$ m) at a depth ranging from 15 to 30 m. The soundings in the central part of the survey area show more variability. A thin conductive overburden is followed by a more resistive layer with resistivity in the range of 80-1800 ${\O}mega$ m. The north and south limits of the central part of the area as revealed by TEM survey are roughly E-W oriented and coincident with the north fault scarp and the southernmost fault detected by the dipole-dipole survey. The pattern of the polar diagrams calculated from tensorial resistivity data clearly indicates the presence of a contact between two blocks at south of the survey area with the low-resistivity block located southwards. The presence of other two faults is not so clear from the polar diagram patterns, but their location can be afforded combining tensorial, dipole-dipole and TEM results. {\textcopyright} 2009 Nanjing Institute of Geophysical Prospecting.}, keywords = {3D modelling, Fracturation, Macroanisotropy, Tensorial resistivity}, issn = {1742-2132}, doi = {10.1088/1742-2132/6/4/007}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72449138142\&partnerID=tZOtx3y1}, author = {Monteiro Santos, Fernando A and Perea, Hector and Massoud, Usama and Plancha, Jo{\~a}o P and Marques, Jorge and Cabral, Jo{\~a}o} } @booklet {Martinez-Loriente2009, title = {{Wide-angle reflection and refraction seismic profile from the outer part of the gulf of Cadiz: nearest-seis cruise}}, journal = {Instrumentation ViewPoint}, number = {8}, year = {2009}, pages = {49}, publisher = {Universitat Polit{\`e}cnica de Catalunya}, abstract = {We will explain the first interpretations from a marine refraction and wideangle reflection seismic profile acquired in the outer part of the Gulf of Cadiz in November 2008, in the framework of the NEAREST-SEIS cruise}, keywords = {Tecnolog{\'\i}a industrial. Tecnolog{\'\i}a mec{\'a}nica, Tecnolog{\'\i}as}, issn = {1886-4864}, url = {http://dialnet.unirioja.es/servlet/articulo?codigo=3202467\&info=resumen\&idioma=ENG}, author = {Mart{\'\i}nez-Loriente, Sara and Sallares, Valenti and Bartolom{\'e}, Rafael and Gr{\`a}cia i Mont, Eulalia} } @article {LoLacono2008, title = {{Acoustic detection of deep coral mounds}}, journal = {Sea Technology}, volume = {49}, number = {8}, year = {2008}, pages = {35{\textendash}38}, issn = {00933651}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-52349109268\&partnerID=tZOtx3y1}, author = {Lo Lacono, Claudio and Gr{\'a}cia, Eul{\`a}lia and Da{\~n}obeitia, Juan Jos{\'e}} } @article {Barckhausen2008, title = {{Birth of an intraoceanic spreading center}}, journal = {Geology}, volume = {36}, number = {10}, year = {2008}, pages = {767}, abstract = {The Cocos-Nazca spreading center is one of the few examples of the formation of a spreading center by splitting of oceanic lithosphere. It was created when the Farallon plate, broke up in the early Miocene following the collision of the Pacific-Farallon spreading center with the North American continent. Much of the ancient Farallon plate corresponding to the area of opening is lost to subduction beneath Central America and South America, but new data from the conjugate area on the Pacific plate allow the first detailed reconstruction of the break-up process. The opening began after chron 7 (25 Ma) at a location of focused crustal extension caused by overlapping spreading centers that had evolved in response to a slight reorientation of a Pacific-Farallon ridge segment. Beginning at chron 6B (22.7 Ma), eastward progressing seafloor spreading started along an axis that most likely migrated toward the region of weak lithosphere created by the Galapagos hotspot. By chron 6 (19.5 Ma), plate splitting from the spreading center to the trench was complete, allowing the fully detached Cocos and Nazca plates to move independently. This kinematic change resulted in a significant ridge jump of the newly established Pacific-Nazca spreading center, a change in plate motion direction of the Nazca plate by 20{\textdegree}clockwise, and a large increase in Pacific-Cocos plate velocity in the middle Miocene. {\textcopyright} 2008 The Geological Society of America.}, keywords = {Central Pacific, Farallon breakup, Galapagos hotspot, Magnetic anomalies}, issn = {0091-7613}, doi = {10.1130/G25056A.1}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-54949104690\&partnerID=tZOtx3y1}, author = {Barckhausen, Udo and Ranero, Cesar R. and Cande, Steven C. and Engels, Martin and Weinrebe, Wilhelm} } @article {Vazquez2008, title = {{Cenozoic deformational structures on the Galicia Bank Region (NW Iberian continental margin)}}, journal = {Marine Geology}, volume = {249}, number = {1-2}, year = {2008}, month = {mar}, pages = {128{\textendash}149}, abstract = {An analysis of Cenozoic tectonics was carried out on the Galicia Bank Region by means of 750~km of single-channel and 155~km of multi-channel vertical seismic profiles and multibeam bathymetry. This work forms part of a general study aimed at determining the geological risk in the wreck area of the Prestige oil tanker. Several structures affecting the post-rift sedimentary units were identified: I) Faults inherited from the Lower Cretaceous propagating rift (reactivated and non-reactivated), including reactivated normal (N-S, NW-SE) and transfer (NE-SW) faults; and II) Structures resulting from compressive episodes in the Paleogene to Upper Miocene and the Upper Miocene to the Present, including a) neotectonic normal faults decoupled from the basement structure, b) folds and flexures and c) reverse faults (NE-SW to ENE-SWS) related to the Bay of Biscay subduction, that are the most striking regional structures. The characterization of structural style, sedimentary post-rift unit deformation and morphological trends were used to carry out a detailed study of the morphostructure of the Galicia Bank Region. Six morphostructural provinces were differentiated, from E to W: 1) the Galicia Interior Basin related to a main graben; 2) the Transitional Zone, which is a horst and graben territory; 3) the Galicia Bank Main Horst; 4) the Half-Graben Domain; 5) the Deep Galicia Margin, whose structure shows rotated blocks; and 6) the Northwestern Flank, characterized by reverse faults. The Transitional Zone and the Galicia Bank provinces are assumed to be the two morphostructural provinces of the Galicia Bank marginal platform. The origin of the Cenozoic deformation must have been related to reactivation processes during the Pyrenean orogeny. We propose that the fault pattern observed in the study area is related to the phase of renewed Mesozoic fault activity. Polyphase extension in the rifting stage and Cenozoic movements have produced an extensional interference pattern that is evident in the physiography. The decouplage between basement tectonics and upper sedimentary unit tectonics suggests the presence of a viscous layer. A thrust-related main antiform related to the Bay of Biscay subduction is proposed to explain the origin of the Galicia Bank morphology. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {Cenozoic, fault reactivation, Galicia Bank, morphostructure, physiography, tectonics}, issn = {00253227}, doi = {10.1016/j.margeo.2007.09.014}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39549103245\&partnerID=tZOtx3y1}, author = {V{\'a}zquez, J.T. and Medialdea, T. and Ercilla, G. and Somoza, L. and Estrada, F. and Fern{\'a}ndez Puga, M.C. and Gallart, J. and Gr{\`a}cia, E. and Maestro, A. and Sayago, M.} } @article {Ferrer2008, title = {{The deep seismic reflection MARCONI-3 profile: Role of extensional Mesozoic structure during the Pyrenean contractional deformation at the eastern part of the Bay of Biscay}}, journal = {Marine and Petroleum Geology}, volume = {25}, number = {8}, year = {2008}, month = {sep}, pages = {714{\textendash}730}, abstract = {The new MARCONI-3 deep seismic profile allows recognition of the upper crustal structure of the eastern part of the Bay of Biscay and the main features of its Alpine geodynamic evolution. It denotes that the easternmost part of the Bay of Biscay consists of a thick wedge of uppermost Cretaceous to Cenozoic synorogenic sediments lying unconformably on the top of a thinned continental crust with the Mesozoic Parentis Basin to the north and the coeval Landes High to the south. The Parentis Basin appears as a major half-graben bounded southwards by a north-dipping planar fault. It is filled by a thick sequence of Jurassic-Upper Cretaceous carbonates affected by salt domes and squeezed diapirs made up of Triassic evaporites and mudstones. These salt tectonic structures also affect the overlying uppermost Cretaceous to Lower Miocene synorogenic deposits which are folded upon these structures. The Landes High includes a thin pre-Upper Cretaceous cover tilted to the south. In the Basque shelf, it is deformed by a basement-involving thrust wedge emplaced during the Late Eocene-Miocene that constitutes the North-Pyrenean contractional front. Geometric relationships and thickness variations depict that this overall structure results from the following. {\textbullet}Mesozoic extensional stage which includes a Late Jurassic (?)-Late Aptian syn-rift stage in which the Parentis Basin formed; and an Albian-early Late Cretaceous post-rift stage in which diapirs of Triassic evaporites grew close to this major fault.{\textbullet}Compressive deformational stage coeval to the Pyrenean orogeny which led to (1) the development of a latest Cretaceous up to Middle Miocene foreland basin; and (2) from Late Eocene, the formation of a basement-involving thrust wedge in the innermost foreland basin, the squeezing of the diapiric structures formed previously in the Parentis Basin and, later (Middle Miocene), the partial inversion of some pre-existent faults located in the southern Parentis Basin margin. This geodynamic evolution together with the structure of the area evidences that the extensional structure resulting from the opening of the Bay of Biscay played an important role both in the location of the North-Pyrenean front and in the North-Pyrenean foreland contractional deformation features. Specially, the lack of significant inversion structures in the Parentis Basin, despite that it belongs to a severely thinned crustal area before the Alpine compression, denotes that the Mesozoic Landes High acted as an important buffer for the propagation of the Pyrenean contractional deformation to the north. This deformational buffer was active until Early Miocene and probably vanished afterwards during the last stages of Pyrenean orogen development when some basement faults reactivated in the Parentis Basin. {\textcopyright} 2008 Elsevier Ltd. All rights reserved.}, keywords = {Bay of Biscay, Cenozoic, Inversion, Mesozoic, Parentis Basin, Pyrenees, Salt tectonics, Seismic profile}, issn = {02648172}, doi = {10.1016/j.marpetgeo.2008.06.002}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-52349092015\&partnerID=tZOtx3y1}, author = {Ferrer, O. and Roca, E. and Benjumea, B. and Mu{\~n}oz, J.A. and Ellouz, N.} } @conference {Shariat-Panahi2008, title = {{Design, Characterization and Calibration of a Short-Period Ocean Bottom Seismometer (OBS)}}, booktitle = {2008 IEEE Instrumentation and Measurement Technology Conference}, year = {2008}, month = {may}, pages = {495{\textendash}500}, publisher = {IEEE}, organization = {IEEE}, abstract = {First part of this paper presents an Ocean Bottom Seismometers (OBS) designed and constructed for mid-term deployments in order to study the earth dynamics and internal structure. Many marine research institutes have developed such equipment, however there is no standard method for their characterization and calibration. The second part discusses the characterization tests based on the international standards carried out to present the specifications of the equipment built. Calibration of the constructed OBS is carried out through an oceanographic cruise using a widely used reference OBS. Data quality of the instruments is evaluated by direct inspection of the corresponding seismic record sections. {\textcopyright}2008 IEEE.}, keywords = {Analog-to-digital converter, Calibration, Datalogger, Dynamic range, Effective number of bits, Geophone, Jitter, Ocean bottom seismometer (OBS), Seismic record section, Time base}, isbn = {978-1-4244-1540-3}, issn = {10915281}, doi = {10.1109/IMTC.2008.4547086}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51349130474\&partnerID=tZOtx3y1}, author = {Shariat-Panahi, S. and M{\`a}nuel, A. and Alegria, F. and Roset, X. and Bermudez, A. and Sallar{\`e}s, V.} } @article {DelaPuente2008, title = {{Discontinuous Galerkin methods for wave propagation in poroelastic media}}, journal = {GEOPHYSICS}, volume = {73}, number = {5}, year = {2008}, month = {sep}, pages = {T77{\textendash}T97}, abstract = {We have developed a new numerical method to solve the heterogeneous poroelastic wave equations in bounded three-dimensional domains. This method is a discontinuous Galerkin method that achieves arbitrary high-order accuracy on unstructured tetrahedral meshes for the low-frequency range and the inviscid case. By using Biot{\textquoteright}s equations and Darcy{\textquoteright}s dynamic laws, we have built a scheme that can successfully model wave propagation in fluid-saturated porous media when anisotropy of the pore structure is allowed. Zero-inflow fluxes are used as absorbing boundary conditions. A continuous arbitrary high-order derivatives time integration is used for the high-frequency inviscid case, whereas a space-time discontinuous scheme is applied for the low-frequency case. We conducted a numerical convergence test of the proposed methods. We used a series of examples to quantify the quality of our numerical results, comparing them to analytic solutions as well as numerical solutions obtained by other methodologies. In particular, a large scale 3D reservoir model showed the method{\textquoteright}s suitability to solve poroelastic wave-propagation problems for complex geometries using unstructured tetrahedral meshes. The resulting method is proved to be high-order accurate in space and time, stable for the low-frequency case, and asymptotically consistent with the diffusion limit. {\textcopyright} 2008 Society of Exploration Geophysicists. All rights reserved.}, issn = {0016-8033}, doi = {10.1190/1.2965027}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-53849111940\&partnerID=tZOtx3y1}, author = {de la Puente, Josep and Dumbser, Michael and K{\"a}ser, Martin and Igel, Heiner} } @article {LoIacono2008b, title = {{Environmental conditions for gravelly and pebbly dunes and sorted bedforms on a moderate-energy inner shelf (Marettimo Island, Italy, western Mediterranean)}}, journal = {Continental Shelf Research}, volume = {28}, number = {2}, year = {2008}, month = {feb}, pages = {245{\textendash}256}, abstract = {Side scan sonar records, sediment textural characteristics, and in-situ field observations were used to study gravelly and pebbly dunes and sorted bedforms on the inner shelf of Marettimo Island, along the northwestern Sicilian shelf. The dunes are composed of coarse sands, gravels and pebbles (D50: 2-16 mm), displaying a symmetrical shape with a wavelength in the range of 1-2.5 m and a height of 0.15-0.30 m. The bedforms are distributed in a patchy pattern in a depth range of 10-50 m, and are described for the first time on a Mediterranean inner shelf. Sorted bedforms are linear morphological features developed almost perpendicular to the coast in the eastern sector of the island between 15 and 50 m water depth. Bottom shear stresses required for sediment entrainment and the generation of the shallower dunes can be reached during strong storms (Hs=5-6 m; Tp=9-11 s), which are not common in the Mediterranean Sea. However, wave storm events recorded in the study area during the last 17 years are not able to generate the coarsest and deeper dunes, suggesting that the stirring mechanism for dune formation is associated with severe storms that have a recurrence interval of more than 17 years. The long-term stability of the coarse bedforms is supported by the permanence of sorted bedforms without significant morphological changes for long periods (>13 years). Therefore, it is shown that processes forming coarse bedforms can occur in tideless and moderate-energy settings like those of the Mediterranean continental shelves, although the morphological features are probably less dynamic and remain unaltered for longer periods than on higher-energy shelves. {\textcopyright} 2007 Elsevier Ltd. All rights reserved.}, keywords = {Gravel dunes, Inner shelf, Italy, Marettimo Island, Mediterranean Sea, Sorted bedforms}, issn = {02784343}, doi = {10.1016/j.csr.2007.08.005}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-37849005401\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Guill{\'e}n, Jorge} } @article {Sahling2008, title = {{Fluid seepage at the continental margin offshore Costa Rica and southern Nicaragua}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {9}, number = {5}, year = {2008}, month = {may}, pages = {n/a{\textendash}n/a}, abstract = {A systematic search for methane-rich fluid seeps at the seafloor was conducted at the Pacific continental margin offshore southern Nicaragua and northern central Costa Rica, a convergent margin characterized by subduction erosion. More than 100 fluid seeps were discovered using a combination of multibeam bathymetry, side-scan sonar imagery, TV-sled observations, and sampling. This corresponds, on average, to a seep site every 4 km along the continental slope. In the northwestern part of the study area, subduction of oceanic crust formed at the East Pacific Rise is characterized by pervasive bending-induced faulting of the oceanic plate and a relatively uniform morphology of the overriding continental margin. Seepage at this part of the margin typically occurs at approximately cone-shaped mounds 50 - 100 m high and up to 1 km wide at the base. Over 60 such mounds were identified on the 240 km long margin segment. Some normal faults also host localized seepage. In contrast, in the southeast, the 220 km long margin segment overriding the oceanic crust formed at the Cocos-Nazca Spreading Centre has a comparatively more irregular morphology caused mainly by the subduction of ridges and seamounts sitting on the oceanic plate. Over 40 seeps were located on this part of the margin. This margin segment with irregular morphology exhibits diverse seep structures. Seeps are related to landslide scars, seamountsubduction related fractures, mounds, and faults. Several backscatter anomalies in side-scan images are without apparent relief and are probably related to carbonate precipitation. Detected fluid seeps are not evenly distributed across the margin but occur in a roughly margin parallel band centered 28 {\textpm} 7 km landward of the trench. This distribution suggests that seeps are possibly fed to fluids rising from the plate boundary along deep-penetrating faults through the upper plate. Copyrignt 2008 by the American Geophysical Union.}, keywords = {Authigenic carbonate, Chemosynthetic community, Subduction erosion}, issn = {15252027}, doi = {10.1029/2008GC001978}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70350099584\&partnerID=tZOtx3y1}, author = {Sahling, Heiko and Masson, Douglas G. and Ranero, Cesar R. and H{\"u}hnerbach, Veit and Weinrebe, Wilhelm and Klaucke, Ingo and B{\"u}rk, Dietmar and Br{\"u}ckmann, Warner and Suess, Erwin} } @article {Ercilla2008, title = {{High-resolution seismic stratigraphy of the Galicia Bank Region and neighbouring abyssal plains (NW Iberian continental margin)}}, journal = {Marine Geology}, volume = {249}, number = {1-2}, year = {2008}, month = {mar}, pages = {108{\textendash}127}, abstract = {The high-resolution seismic stratigraphy of the Galicia Bank Region and adjacent deposits of the neighbouring Iberian and Biscay Abyssal Plains was included as part of the geological studies conducted in the area where the oil-tanker Prestige wreck is located. This seismic stratigraphy is characterized by five seismic units (5 to 1, from oldest to youngest) lying above an irregular acoustic basement defined by a highly fractured system of horsts and grabens. These faulted systems have controlled the local depositional architecture, deforming, fracturing, relocating and distributing sediments since the Valanginian. Three depositional models of facies can be recognized on the Galicia Bank Region and surrounding abyssal plains: bank, escarpment, and abyssal plain facies. The bank facies reflects the depositional evolution from initial filling to obliterating stages of the horsts and grabens. The escarpment facies has a local distribution and represents deposition associated with active slopes of the faulted escarpments. The abyssal plain facies represents gravity flow deposits coming mostly from the bounded-fault flanks of the Galicia Bank Region. The Valanginian to Quaternary sedimentary evolution of the Galicia Bank Region reflects depositional responses to tectonic condition. The occurrence of mass-movements confirms that the syn-rift period (Valanginian to Aptian age) along the Galicia margin was diachronous, beginning in the Interior Basin and shifting later toward the west of the Galicia Bank Region (Deep Galicia Margin). The Albian to Quaternary post-rift evolution is characterized by a decrease in tectonic activity and sedimentary variations in the style of deposition (valley and related features, mass-movement deposits, contourites, and drape deposits) conditioned by changes in the sedimentary processes, paleoenvironments, and tectonic reactivation of the regional slopes. The effects of tectonic movements persist, as evidenced in areas where faulted escarpments and highs outcrop, and in areas of near-surface faulting. The syn-rift and post-rift stages have also conditioned the depositional architecture of the Prestige sinking area. The evolution of the surrounding abyssal plains does not reflect the same pattern to tectonic condition. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {facies architecture, Galicia Bank, high-resolution seismic profiles, sedimentary evolution, seismic facies, stratigraphy}, issn = {00253227}, doi = {10.1016/j.margeo.2007.09.009}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39649109232\&partnerID=tZOtx3y1}, author = {Ercilla, G. and Garc{\'\i}a-Gil, S. and Estrada, F. and Gr{\`a}cia, E. and Vizcaino, A. and V{\'a}quez, J.T. and D{\'\i}az, S. and Vilas, F. and Casas, D. and Alonso, B. and Da{\~n}obeitia, J. and Farran, M.} } @article {Ranero2008, title = {{Hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {9}, number = {3}, year = {2008}, month = {mar}, pages = {n/a{\textendash}n/a}, abstract = {Fluid distribution in convergent margins is by most accounts closely related to tectonics. This association has been widely studied at accretionary prisms, but at half of the Earth{\textquoteright}s convergent margins, tectonic erosion grinds down overriding plates, and here fluid distribution and its relation to tectonics remain speculative. Here we present a new conceptual model for the hydrological system of erosional convergent margins. The model is based largely on new data and recently published observations from along the Middle America Trench offshore Nicaragua and Costa Rica, and it is consistent with observations from other erosional margins. The observations indicate that erosional margins possess previously unrecognized distinct hydrogeological systems: Most fluid contained in the sediment pores and liberated by early dehydration reactions drains from the plate boundary through a fractured upper plate to seep at the seafloor across the slope, rather than migrating along the d{\'e}collement toward the deformation front as described for accretionary prisms. The observations indicate that the relative fluid abundance across the plate-boundary fault zone and fluid migration influence long-term tectonics and the transition from aseismic to seismogenic behavior. The segment of the plate boundary where fluid appears to be more abundant corresponds to the locus of long-term tectonic erosion, where tectonic thinning of the overriding plate causes subsidence and the formation of the continental slope. This correspondence between observations indicates that tectonic erosion is possibly linked to the migration of overpressured fluids into the overriding plate. The presence of overpressured fluids at the plate boundary is compatible with the highest flow rates estimated at slope seeps. The change from aseismic to seismogenic behavior along the plate boundary of the erosional margin begins where the amount of fluid at the fault declines with depth, indicating a control on interplate earthquakes. A previously described similar observation along accreting plate boundaries strongly indicates that fluid abundance exerts a first-order control on interplate seismogenesis at all types of subduction zones. We hypothesize that fluid depletion with depth increases grain-to-grain contact, increasing effective stress on the fault, and modifies fault zone architecture from a thick fault zone to a narrower zone of localized slip. Copyright 2008 by the American Geophysical Union.}, keywords = {fluid flow, Seismogenesis, subduction zones, Tectonic erosion}, issn = {15252027}, doi = {10.1029/2007GC001679}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67349265252\&partnerID=tZOtx3y1}, author = {Ranero, C. R. and Grevemeyer, I. and Sahling, H. and Barckhausen, U. and Hensen, C. and Wallmann, K. and Weinrebe, W. and Vannucchi, P. and von Huene, R. and McIntosh, K.} } @article {Biescas2008, title = {{Imaging meddy finestructure using multichannel seismic reflection data}}, journal = {Geophysical Research Letters}, volume = {35}, number = {11}, year = {2008}, month = {jun}, pages = {L11609}, abstract = {This work illustrates the great potential of multichannel seismic reflection data to extract information from the finestructure of meddies with exceptional lateral resolution (10-15 m). We present seismic images of three meddies acquired in the Gulf of Cadiz (SW Iberian Peninsula), which consist of concentric reflectors forming oval shapes that sharply contrast with the background oceanic structure. The seismic images reveal the presence of different regions within the meddies that are consistent with those observed in historical temperature (T) and salinity (S) data. The core region, characterized by smooth T and S variations, is weakly reflective. The double-diffusive upper and lower boundaries and the lateral-interleaving outer edges, characterized by stronger T and S contrasts, display strong reflectivity bands. These new observations clearly show differences between layers developed at the upper and lower boundaries that can contribute to th knowledge of mixing processes and layering formation in oceans. Copyright 2008 by the American Geophysical Union.}, issn = {0094-8276}, doi = {10.1029/2008GL033971}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-49849096389\&partnerID=tZOtx3y1}, author = {Biescas, B. and Sallar{\`e}s, V. and Pelegr{\'\i}, J. L. and Mach{\'\i}n, F. and Carbonell, R. and Buffett, G. and Danobeitia, J. J. and Calahorrano, A.} } @article {PhippsMorgan2008, title = {{Intra-arc extension in Central America: Links between plate motions, tectonics, volcanism, and geochemistry}}, journal = {Earth and Planetary Science Letters}, volume = {272}, number = {1-2}, year = {2008}, pages = {365{\textendash}371}, abstract = {This study revisits the kinematics and tectonics of Central America subduction, synthesizing observations of marine bathymetry, high-resolution land topography, current plate motions, and the recent seismotectonic and magmatic history in this region. The inferred tectonic history implies that the Guatemala-El Salvador and Nicaraguan segments of this volcanic arc have been a region of significant arc tectonic extension; extension arising from the interplay between subduction roll-back of the Cocos Plate and the \~{} 10-15mm/yr slower westward drift of the Caribbean plate relative to the North American Plate. The ages of belts of magmatic rocks paralleling both sides of the current Nicaraguan arc are consistent with long-term arc-normal extension in Nicaragua at the rate of \~{} 5-10mm/yr, in agreement with rates predicted by plate kinematics. Significant arc-normal extension can {\textquoteright}hide{\textquoteright} a very large intrusive arc-magma flux; we suggest that Nicaragua is, in fact, the most magmatically robust section of the Central American arc, and that the volume of intrusive volcanism here has been previously greatly underestimated. Yet, this flux is hidden by the persistent extension and sediment infill of the rifting basin in which the current arc sits. Observed geochemical differences between the Nicaraguan arc and its neighbors which suggest that Nicaragua has a higher rate of arc-magmatism are consistent with this interpretation. Smaller-amplitude, but similar systematic geochemical correlations between arc-chemistry and arc-extension in Guatemala show the same pattern as the even larger variations between the Nicaragua arc and its neighbors. {\textcopyright} 2008 Elsevier B.V. All rights reserved.}, keywords = {arc geochemistry, Central America, extension, magmatism, Plate Tectonics}, issn = {0012821X}, doi = {10.1016/j.epsl.2008.05.004}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-47749095517\&partnerID=tZOtx3y1}, author = {Phipps Morgan, J. and Ranero, C.R. and Vannucchi, P.} } @article {Goldfinger2008, title = {{Late Holocene Rupture of the Northern San Andreas Fault and Possible Stress Linkage to the Cascadia Subduction Zone}}, journal = {Bulletin of the Seismological Society of America}, volume = {98}, number = {2}, year = {2008}, month = {apr}, pages = {861{\textendash}889}, abstract = {We relate the late Holocene northern San Adreas fault (NSAF) paleoseismic history developed using marine sediment cores along the northern California continental margin to a similar dataset of cores collected along the Cascadia margin, including channels from Barclay Canyon off Vancouver Island to just north of Monterey Bay. Stratigraphic correlation and evidence of synchronous triggering imply earthquake origin, and both temporal records are compatible with onshore paleoseismic data. In order to make comparisons between the temporal earthquake records from the NSAF and Cascadia, we refine correlations of southern Cascadia great earthquakes, including the land paleoseismic record. Along the NSAF during the last \~{}2800 yr, 15 turbidites, including one likely from the great 1906 earthquake, establish an average repeat time of \~{}200 yr, similar to the onshore value of \~{}240 yr. The combined land and marine paleoseismic record from the southern Cascadia subduction zone includes a similar number of events during the same period. While the average recurrence interval for full-margin Cascadia events is \~{}520 yr, the southern Cascadia margin has a repeat time of \~{}220 yr, similar to that of the NSAF. Thirteen of the 15 NSAF events were preceded by Cascadia events by \~{}0-80 yr, averaging 25-45 yr (as compared to \~{}80-400 yr by which Cascadia events follow the NSAF). Based on the temporal association, we model the coseismic and cumulative postseismic deformation from great Cascadia megathrust events and compute related stress changes along the NSAF in order to test the possibility that Cascadia earthquakes triggered the penultimate, and perhaps other, NSAF events. The Coulomb failure stress (CFS) resulting from viscous deformation related to a Cascadia earthquake over \~{}60 yr does not contribute significantly to the total CFS on the NSAF. However, the coseismic deformation increases CFS on the northern San Andreas fault (NSAF) by up to about 9 bars offshore of Point Delgada, most likely enough to trigger that fault to fail in north-to-south propagating ruptures.}, issn = {0037-1106}, doi = {10.1785/0120060411}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-42649087275\&partnerID=tZOtx3y1}, author = {Goldfinger, C. and Grijalva, K. and Burgmann, R. and Morey, A. E. and Johnson, J. E. and Nelson, C. H. and Gutierrez-Pastor, J. and Ericsson, A. and Karabanov, E. and Chaytor, J. D. and Patton, J. and Gr{\`a}cia, E.} } @article {Panahi2008, title = {{A Low-Power Datalogger Based on CompactFlash Memory for Ocean Bottom Seismometers}}, journal = {IEEE Transactions on Instrumentation and Measurement}, volume = {57}, number = {10}, year = {2008}, month = {oct}, pages = {2297{\textendash}2303}, abstract = {In the last decade, marine scientific instruments have been in high demand, particularly autonomous instruments that are capable of staying under water for a long time while performing continuous data acquisition and storage. This paper introduces an instrument under development that is used for the study of ocean bottom sublayers and microseismic detection. The power consumption of the equipment has been minimized to increase autonomy, and CompactFlash memory cards have been used as the storage element. Development of such equipment is a joint effort between different disciplines, such as electronics, mechanics, geophysics, underwater communications, etc. The acquisition system was tested both in the laboratory and under real environmental conditions in the summer of 2005, and the results have been evaluated. {\textcopyright} 2008 IEEE.}, keywords = {Analog-to-digital (A/D) converter, CompactFlash memory, Datalogger, Effective number of bits (ENOB), Ocean bottom seismometer (OBS), Power consumption, Time base}, issn = {0018-9456}, doi = {10.1109/TIM.2008.919005}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-52649175960\&partnerID=tZOtx3y1}, author = {Panahi, S.S. and Ventosa, S. and Cadena, J. and Manuel-Lazaro, A. and Bermudez, A. and Sallar{\`e}s, V. and Piera, J.} } @article {Latham2008a, title = {{Modelling of massive particulates for breakwater engineering using coupled FEMDEM and CFD}}, journal = {Particuology}, volume = {6}, number = {6}, year = {2008}, month = {dec}, pages = {572{\textendash}583}, abstract = {The seaward slope of many breakwaters consists of thousands of interlocking units of rock or concrete comprising a massive granular system of large elements each weighing tens of tonnes. The dumped quarry materials in the core are protected by progressively coarser particulates. The outer armour layer of freely placed units is intended to both dissipate wave energy and remain structurally stable as strong flows are drawn in and out of the particulate core. Design guidance on the mass and shape of these units is based on empirical equations derived from scaled physical model tests. The main failure mode for armour layers exposed to severe storms is hydraulic instability where the armour units of concrete or rock are subjected to uplift and drag forces which can in turn lead to rocking, displacement and collisions sufficient to cause breakage of units. Recently invented armour unit designs making up such granular layered system owe much of their success to the desirable emergent properties of interlock and porosity and how these combine with individual unit structural strength and inertial mass. Fundamental understanding of the forces governing such wave-structure interaction remains poor. We use discrete element and combined finite-discrete element methods to model the granular solid skeleton of randomly packed units coupled to a CFD code which resolves the wave dynamics through an interface tracking technique. The CFD code exploits several methods including a compressive advection scheme, node movement, and general mesh optimization. We provide the engineering context and report progress towards the numerical modelling of instability in these massive granular systems. {\textcopyright} 2008 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.}, keywords = {Armour units, Breakwater, DEM, Modelling, Wave-structure interaction}, issn = {16742001}, doi = {10.1016/j.partic.2008.07.010}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57049161892\&partnerID=tZOtx3y1}, author = {Latham, John-Paul and Munjiza, Antonio and Mindel, Julian and Xiang, Jiansheng and Guises, Romain and Garcia, Xavier and Pain, Chris and Gorman, Gerard and Piggott, Matthew} } @article {Klaucke2008, title = {{Multifrequency geoacoustic imaging of fluid escape structures offshore Costa Rica: Implications for the quantification of seep processes}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {9}, number = {4}, year = {2008}, month = {apr}, pages = {n/a{\textendash}n/a}, abstract = {Quantification of fluid fluxes from cold seeps depends on accurate estimates of the spatial validity of flux measurements. These estimates are strongly influenced by the choice of geoacoustic mapping tools. Multibeam bathymetry, side-scan sonar, and Chirp subbottom profiler data of several mound-shaped cold seeps offshore central Costa Rica show great variety in morphology and structure although the features are only a few kilometers apart. Mound 11 (a 35 m high and 1000 m in diameter structure), situated in the SE of the study area, has an irregular morphology but a smooth surface on side-scan sonar data, while mound 12 (30 m high, 600 m across) is a cone of more regular outline but with a rough surface, and mound Grillo (5 m high, 500 m across) shows the same rough surface as mound 12 but without relief. Video observations and sediment cores indicate that the structures are formed by the precipitation of authigenic carbonates and indications for extensive mud extrusion are absent, except for one possible mudflow at mound 11. Different sonar frequencies result in variable estimates of the extent of these mounds with low frequencies suggesting much wider cold seeps, consequently overestimating fluid fluxes. The absence of mud volcanism compared to accretionary prisms where mud volcanism occurs is related to different tectonic styles: strong sediment overpressure and thrust faulting in typical accretionary prisms can generate mud volcanism, while subduction erosion and normal faulting (extension) of the overriding plate at the Costa Rican margin result in fluid venting driven by only slight fluid overpressures. Copyright 2008 by the American Geophysical Union.}, keywords = {Cold seeps, Costa Rica, Side-scan sonar}, issn = {15252027}, doi = {10.1029/2007GC001708}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-71749104881\&partnerID=tZOtx3y1}, author = {Klaucke, Ingo and Masson, Douglas G. and Petersen, C. J{\"o}rg and Weinrebe, Wilhelm and Ranero, Cesar R.} } @article {Rodriguez2008, title = {{A new multi-platform modular software tool for wide-angle reflection/refraction seismic data processing and representation (WASPAR)}}, journal = {Computers \& Geosciences}, volume = {34}, number = {5}, year = {2008}, pages = {456{\textendash}463}, abstract = {WASPAR (Wide-Angle reflection-refraction Seismic data Processing And Representation) is a new free multi-platform software tool to process and display wide-angle seismic data. It has been designed to read different raw data formats, construct record sections, process them using existing and newly developed algorithms, pick seismic phases and generate graphic files using a single, user-friendly interface. The main characteristics of WASPAR are its flexibility and expandability. It has been designed in a modular way using a plug-in architecture to manage raw data access and processing functionalities. We thus obtain a stable base easily maintainable and expandable. We have chosen the C ++ programming language in combination with an object oriented methodology to facilitate the development of a multi-platform software tool, which is already available on Linux and MS Windows. In order to allow its expansion and upgrade, the program will be freely distributed under the terms of GPL license. The philosophy of this software tool is to leave it open to external contributions. {\textcopyright} 2007 Elsevier Ltd. All rights reserved.}, keywords = {Object oriented programming, Plug-in, Signal processing, Software, wide-angle seismics}, issn = {00983004}, doi = {10.1016/j.cageo.2007.04.011}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39149086998\&partnerID=tZOtx3y1}, author = {Rodr{\'\i}guez, I. and Simon, C. and Sallar{\`e}s, V. and Carlosena, A. and M{\`a}nuel, A. and Da{\~n}obeitia, J.J.} } @article {CALAHORRANOB2008, title = {{Nonlinear variations of the physical properties along the southern Ecuador subduction channel: Results from depth-migrated seismic data}}, journal = {Earth and Planetary Science Letters}, volume = {267}, number = {3-4}, year = {2008}, pages = {453{\textendash}467}, abstract = {We use two high-quality pre-stack depth-migrated multichannel seismic profiles acquired to quantify physical properties variations of underthrust sediments along the first \~{} 30~km of subduction off the erosional southern Ecuadorian margin. Seismic data show three zones along the subduction channel (referred to as Zones I, II and III) characterized by distinct velocity and velocity-derived physical properties, which are in agreement with values estimated from experimental results of deformation in granular media. These three zones result from transformational changes of underthrust sediments governed by fundamentally different physical processes that control their mechanical behavior at increasing confining pressures. Based on our observations and its comparison with experimental results, we argue that the transformations undergone by underthrust sediments as they dip into the subduction zone are the following: within Zone I, progressively increasing velocity (and decreasing velocity-derived porosity) indicates continuous sediment compaction, which must be accompanied by effective fluid drainage along the d{\'e}collement and/or across the accretionary wedge. The underthrust material is here unconsolidated from a mechanical point of view. Laboratory experiments indicate that the dominant processes at this range of pressures are grain rolling, particle rotation and frictional slip at grain contacts. Within Zone II, velocity (and porosity) remains constant for \~{} 16~km (SIS-72) and \~{} 12~km (SIS-18). This suggests undrained conditions resulting in growing fluid overpressure at the subduction channel. Grain deformation is similar to Zone I. Within Zone III, velocity increases and porosity falls rapidly, indicating sediment compaction and subsequent release of over-pressured fluids, where grain deformation is likely to be elastic. This might be the dominant process until the grains attain their crushing strength, resulting in granular cataclasis and, eventually, in the collapse of the system. We suggest that over-pressured fluid release may induce hydrofracturation and it is likely to increase inter-plate coupling down from Zone III. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {fluid overpressure, grain deformation, subduction channel, velocity inversion}, issn = {0012821X}, doi = {10.1016/j.epsl.2007.11.061}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39649120786\&partnerID=tZOtx3y1}, author = {CALAHORRANOB, A and SALLARES, V and COLLOT, J and SAGE, F and RANERO, C} } @conference {Shariat-Panahi2008a, title = {{Ocean Bottom Seismometer (OBS): An instrument for marine seismic data acquisition}}, booktitle = {2008 IEEE International Symposium on Industrial Electronics}, year = {2008}, month = {jun}, pages = {1183{\textendash}1186}, publisher = {IEEE}, organization = {IEEE}, abstract = {The OBS (Ocean Bottom Seismoemter) has been a key instrument for geophysical study of sea sub-bottom layers in the last decades. Now scientists are demanding highly relaible autonomous equipment capable of staying underwater for long periods of time and therefore handling large data storage. Power consumption of the acquisition system as well as a stable time base with temperature are the main issues in order to achieve high autonomy together with a good data quality. This paper presents a new Ocean Bottom Seismometer designed to be used in marine mid-term surveys. To achieve our goals, a new low power datalogger with high resolution and Signal-to-Noise Ratio (SNR) based on Compactflash memory card is designed to enable continous data acquisition. The equipment has been evaluated in real environmental conditions during a test cruise in 2006. {\textcopyright} 2008 IEEE.}, keywords = {Acquisition system, Analog to digital converter, Geophone, Ocean bottom seismometer (OBS)}, isbn = {978-1-4244-1665-3}, doi = {10.1109/ISIE.2008.4677225}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57849111983\&partnerID=tZOtx3y1}, author = {Shariat-Panahi, S. and M{\`a}nuel, A. and Bermudez, A. and Ambros, M. and Sallar{\`e}s, V. and Molino, E.} } @article {Secanell2008, title = {{Probabilistic seismic hazard assessment of the Pyrenean region}}, journal = {Journal of Seismology}, volume = {12}, number = {3}, year = {2008}, month = {mar}, pages = {323{\textendash}341}, abstract = {A unified probabilistic seismic hazard assessment (PSHA) for the Pyrenean region has been performed by an international team composed of experts from Spain and France during the Interreg IIIA ISARD project. It is motivated by incoherencies between the seismic hazard zonations of the design codes of France and Spain and by the need for input data to be used to define earthquake scenarios. A great effort was invested in the homogenisation of the input data. All existing seismic data are collected in a database and lead to a unified catalogue using a local magnitude scale. PSHA has been performed using logic trees combined with Monte Carlo simulations to account for both epistemic and aleatory uncertainties. As an alternative to hazard calculation based on seismic sources zone models, a zoneless method is also used to produce a hazard map less dependant on zone boundaries. Two seismogenic source models were defined to take into account the different interpretations existing among specialists. A new regional ground-motion prediction equation based on regional data has been proposed. It was used in combination with published ground-motion prediction equations derived using European and Mediterranean data. The application of this methodology leads to the definition of seismic hazard maps for 475- and 1,975-year return periods for spectral accelerations at periods of 0 (corresponding to peak ground acceleration), 0.1, 0.3, 0.6, 1 and 2 s. Median and percentiles 15\% and 85\% acceleration contour lines are represented. Finally, the seismic catalogue is used to produce a map of the maximum acceleration expected for comparison with the probabilistic hazard maps. The hazard maps are produced using a grid of 0.1{\textdegree}. The results obtained may be useful for civil protection and risk prevention purposes in France, Spain and Andorra. {\textcopyright} Springer Science+Business Media B.V. 2008.}, keywords = {Andorra, France, Monte Carlo, Probabilistic, Seismic hazard, Seismic zonation, Spain}, issn = {1383-4649}, doi = {10.1007/s10950-008-9094-2}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-46349102115\&partnerID=tZOtx3y1}, author = {Secanell, R. and Bertil, D. and Martin, C. and Goula, X. and Susagna, T. and Tapia, M. and Dominique, P. and Carbon, D. and Fleta, J.} } @article {Kaser2008, title = {{Quantitative accuracy analysis of the discontinuous Galerkin method for seismic wave propagation}}, journal = {Geophysical Journal International}, volume = {173}, number = {3}, year = {2008}, month = {jun}, pages = {990{\textendash}999}, abstract = {We present a quantitative accuracy analysis of the Discontinuous Galerkin Finite-Element method for the simulation of seismic wave propagation on tetrahedral meshes. Several parameters are responsible for the accuracy of results, such as the chosen approximation order, the spatial discretization, that is, number of elements per wavelength, and the propagation distance of the waves due to numerical dispersion and dissipation. As error norm we choose the time-frequency representation of the envelope and phase misfit of seismograms to assess the accuracy of the resulting seismograms since this provides the time evolution of the spectral content and allows for the clear separation of amplitude and phase errors obtained by the numerical method. Our results can be directly used to set up the necessary modelling parameters for practical applications, such as the minimum approximation order for a given mesh spacing to reach a desired accuracy. Finally, we apply our results to the well-acknowledged LOH.1 and LOH.3 problems of the SPICE Code Validation project, including heterogeneous material and the free surface boundary condition, and compare our solutions with those of other methods. In general, we want to stress the increasing importance of certain standard procedures to facilitate future code validations and comparisons of results in the community of numerical seismology. {\textcopyright} 2008 The Authors Journal compilation {\textcopyright} 2008 RAS.}, keywords = {Computational seismology, Numerical approximations and analysis, Numerical solutions, Time series analysis, Wave propagation, Wavelet transform}, issn = {0956540X}, doi = {10.1111/j.1365-246X.2008.03781.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-43749087643\&partnerID=tZOtx3y1}, author = {K{\"a}ser, Martin and Hermann, Verena and de la Puente, Josep} } @article {Hernandez-Molina2008, title = {{Recent sedimentary processes in the Prestige site area (Galicia Bank, NW Iberian Margin) evidenced by high-resolution marine geophysical methods}}, journal = {Marine Geology}, volume = {249}, number = {1-2}, year = {2008}, month = {mar}, pages = {21{\textendash}45}, abstract = {An echo-character analysis of the oil tanker Prestige wreck area was undertaken using high-resolution marine geophysical methods (TOPAS and airgun seismic-reflection profiles, multibeam echosounder and TOBI sidescan sonar). Integration and comparison of the results using all these methods is presented given some practical applications for indirect near-surface and seafloor interpretations. Ten different echo types were identified and grouped into four main classes: I) distinct; II) indistinct; III) irregular and IV) hyperbolic. Echo-character distribution enabled us to determine recent sedimentary processes in the area. Two major depositional systems can be found through the identification of these sedimentary processes: a) a slope depositional system (SDS) located in the eastern and central area, where mass-movement processes are dominant and b) a turbiditic Main Channel depositional system (TDS) located in the western area where channel-related processes are dominant. Both of these interact over the half-graben structure of the southwestern sector of the Galicia Bank, where the Prestige wreck is located. Within the SDS, erosive and depositional mass-movement processes characterised a complex depositional system. Erosive processes occur on the fault scarp, channels head, inter-lobe channels and distal part of the sedimentary lobes. Moreover, depositional processes take place on the top of the fault scarp, sedimentary wedges, sedimentary lobes, and on the west flank of the Main Channel. Both depositional systems interact, but the SDS should be more active during fault-scarp reactivation periods, through relief rejuvenation and new exposed deposits. Microearthquake activity would favour the available materials, being weathered, eroded and transported by mass-movements. In such a situation, the TDS acts as the main collector of eroded sediment derived from the fault scarp throughout the SDS being responsible for its evacuation into the Iberian Abyssal Plain. However, outside of fault reactivation periods, the SDS is less active (such as during the present situation). {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {echo-character analysis, Galicia Bank, high-resolution seismic profiles, sedimentary process, swath bathymetry, TOBI sidescan sonar}, issn = {00253227}, doi = {10.1016/j.margeo.2007.09.011}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39549115454\&partnerID=tZOtx3y1}, author = {Hern{\'a}ndez-Molina, F.J. and Llave, E. and Ercilla, G. and Maestro, A. and Medialdea, T. and Ferrin, A. and Somoza, L. and Gr{\`a}cia, E. and Masson, D.G. and Garc{\'\i}a, M. and Vizcaino, A. and Le{\'o}n, R.} } @article {Garcia2008, title = {{Robust processing of magnetotelluric data in the AMT dead band using the continuous wavelet transform}}, journal = {GEOPHYSICS}, volume = {73}, number = {6}, year = {2008}, month = {nov}, pages = {F223{\textendash}F234}, abstract = {The energy sources for magnetotellurics (MT) at frequencies above 8 Hz are electromagnetic waves generated by distant lightning storms propagating globally within the earth-ionosphere waveguide. The nature of the sources and properties of this waveguide display diurnal and seasonal variations that can cause significant signal amplitude attenuation, especially at 1-5 kHz frequencies - the so-called audiomagnetotelluric (AMT) dead band. This lack of energy results in unreliable MT response estimates; and, given that in crystalline environments ore bodies located at some 500-1000-m depth are sensed initially by AMT data within the dead band, this leads to poor inherent geometric resolution of target structures. We propose a new time-series processing technique that uses localization properties of the wavelet transform to select the most energetic events. Subsequently, two coherence thresholds and a series of robust weights are implemented to obtain the most reliable MT response estimates. Finally, errors are estimated using a nonparametric jackknife algorithm. We applied this algorithm to AMT data collected in northern Canada. These data were processed previously using traditional robust algorithms and using a telluric-telluric magnetotelluric (TTMT) technique. The results show a significant improvement in estimates for the AMT dead band and permit their quantitative interpretation. {\textcopyright} 2008 Society of Exploration Geophysicists. All rights reserved.}, issn = {0016-8033}, doi = {10.1190/1.2987375}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57149105924\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Jones, Alan G.} } @article {LoIacono2008, title = {{Seafloor characterization and backscatter variability of the Almer{\'\i}a Margin (Alboran Sea, SW Mediterranean) based on high-resolution acoustic data}}, journal = {Marine Geology}, volume = {250}, number = {1-2}, year = {2008}, month = {apr}, pages = {1{\textendash}18}, abstract = {An acoustic study of the Almer{\'\i}a Margin (eastern Alboran Sea, SW Mediterranean) was carried out by means of an integrated dataset, comprising deep-towed TOBI sidescan sonar, swath-bathymetry, TOPAS high-resolution seismics and sediment gravity cores. The Almer{\'\i}a Margin is a complex system dominated by volcanic and tectonic features shaped by recent sedimentary processes, in which a regional hemipelagic sedimentation is intercalated by sporadic gravitative events. The aim of this work is twofold. The first objective is to recognize the sedimentary and tectonic features that shape the Almeria Margin. The main morpho-sedimentary and morpho-structural elements observed are: the Almer{\'\i}a canyon/channel Turbidite System, the Dal{\'\i}as Tributary Valley System, landslides, active faults and folds and volcanic banks. The second aim is to explore and quantify the surface and subsurface seafloor parameters that characterize the backscatter of the study area. Sedimentary, geomorphological and biological elements that play a role in the acoustic signature of the Almer{\'\i}a Margin were detected. Nevertheless, it should be noted that seafloor acoustic backscatter is also affected by geometrical and instrumental factors. Despite the wide variability of the environments studied, a low average acoustic backscatter reflects a diffused draping of hemipelagic sedimentation in the area. Higher backscatter values were observed at the top of some volcanic banks, along the Almer{\'\i}a canyon, and in the shallower sector of the Dal{\'\i}as tributary valley system. The influence of subseafloor properties in the acoustic signature of the area was revealed by backscatter-grain size correlations, which were carried out for different depth intervals in sediment cores collected in the Almer{\'\i}a Turbidite System. A poor relationship was found between backscatter and superficial silty sediments of the area, whereas a higher correlation resulted in the upper 50~cm. The presence of subsurface turbidites in the cores associated with the higher backscatter values suggests volume interface scattering of these sandy layers as a controlling factor of the acoustic signature obtained in the Almer{\'\i}a Margin. On the other hand, in rough settings such as the ones observed in the Dal{\'\i}as Tributary Valley System, topographic relief of up to 1-1.5~m strongly interacted with the TOBI acoustic pulse. This suggests that large-scale roughness is an additional parameter that characterizes the acoustic strength of the area. Extremely high reflective patches distributed along some of the volcanic banks (Chella and Pollux Banks) for depths ranging from 230 to 470~m coincide with areas where carbonate cold water coral mounds develop. In the TOBI images, coral facies reach the maximum value of acoustic backscatter, which is probably related to the rough morphology of coral ecosystems. The position of coral mounds in the banks suggests that the occurrence of strong bottom currents and reduced sedimentary inputs are environmental factors that favour their settling and development in the Almer{\'\i}a Margin. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {backscatter, coral mounds, deep-towed sidescan sonar TOBI, high-resolution seismics, Mediterranean Sea, South Iberian Margin, swath-bathymetry}, issn = {00253227}, doi = {10.1016/j.margeo.2007.11.004}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-41349119993\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Gr{\'a}cia, Eul{\`a}lia and Diez, Susana and Bozzano, Graziella and Moreno, Ximena and Da{\~n}obeitia, Juanjo and Alonso, Bel{\'e}n} } @book {Puente2008, title = {{Seismic Wave Propagation for Complex Rheologies}}, year = {2008}, abstract = {Seismic waves are produced whenever a large amount of energy is released under the surface of the Earth, for example when earthquakes occur. Such waves are perturbed by the heterogeneities they find in their travel through the subsurface, from hypocenter to seismometer. In the last decades, the increase in computational power has made it possible to simulate the propagation of seismic waves in fully 3D heterogeneous media. However, the subsoil often displays very complicated geometrical structures which are difficult to nest by nowadays simulation methods. The ADER-DG (Arbitrary high-order DERivatives Discontinuous Galerkin) method provides the means to better represent subsoil geological structures using tetrahedral meshes. Such meshes can be easily deformed and adapted to very complicated geometries such as folded layers, faults and shallow basins. In this book the ADER-DG method is developed for problems of elastodynamics and further extended to accommodate anisotropic, viscoelastic and poroelastic rheologies. For all cases examples are provided to verify the fast convergence properties and to show the precision of the synthetic seismograms computed.}, isbn = {3639016793}, url = {http://books.google.es/books/about/Seismic\_Wave\_Propagation\_for\_Complex\_Rhe.html?id=oqbVOQAACAAJ\&pgis=1}, author = {Puente, Josep De La} } @article {Garcia2008a, title = {{Strong-weak network anisotropy switching and hysteresis in three-dimensional granular materials}}, journal = {Physical Review E}, volume = {78}, number = {2}, year = {2008}, pages = {021305}, abstract = {We address hysteresis of three-dimensional polydisperse granular packs, comparing macro- and microscopic viewpoints, to reveal their elastic/inelastic mechanics and force network anisotropy. During the uniaxial loading-unloading cycle of an appropriately prepared pack, one can decompose the force network into weak and strong subnetworks. The first stages of loading exhibit arching, where all the fabric displays negative anisotropy. For later stages, the strong (weak) network shows positive (negative) anisotropy. On unloading, the force network progresses to a fabric wide hydrostatic point, where the anisotropies of the weak and strong subnetworks switch signs. During the loading stage, a Mohr circle analysis permits the identification of a well-defined macroscopic internal friction angle, whose value is larger than that of grain-grain interactions. To analyze unloading, a generalized local Coulomb-friction argument predicts a continuously changing friction angle, that vanishes at the hydrostatic point. A suggestive interplay between microscopic friction and fabric structure, at different loding stages, is proposed as the mechanism for the emergence of a macro internal friction angle. {\textcopyright} 2008 The American Physical Society.}, issn = {1539-3755}, doi = {10.1103/PhysRevE.78.021305}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-50849085166\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Medina, Ernesto} } @article {Latham2008, title = {{Three-dimensional particle shape acquisition and use of shape library for DEM and FEM/DEM simulation}}, journal = {Minerals Engineering}, volume = {21}, number = {11}, year = {2008}, month = {oct}, pages = {797{\textendash}805}, abstract = {Numerical simulation that will capture the complex behaviour of rock fragment systems, e.g., in mining and civil engineering, requires both the computational mechanics capability to model particle interactions between complex shapes and an associated means to represent the kind of arbitrary or angular geometry relevant to problems involving rock fragments. This paper is concerned less with the modelling and more with the representation. Here, we focus on representation geared to {\textquoteright}soft contact{\textquoteright} modelling using either combined finite-discrete element (FEM/DEM) methods, or non-spherical DEM methods such as multi-sphere approximations of irregular geometry. 3D laser ranging (LADAR) is used to capture astonishingly realistic rock aggregate geometries. We report on the work flow procedures to generate computationally meshed virtual particles for modelling. The design of a shape library and a suggested procedure for selecting virtual particles for input to FEM/DEM or DEM models is discussed together with the use of inertia moments for shape descriptors. Use of the shape library for shape descriptor analysis is also illustrated. DEM simulations of packing using irregular particles from the shape library are presented. {\textcopyright} 2008 Elsevier Ltd. All rights reserved.}, keywords = {Discrete element modelling, Gravity concentration, Mineral processing, Simulation, Sorting methods}, issn = {08926875}, doi = {10.1016/j.mineng.2008.05.015}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-50149086948\&partnerID=tZOtx3y1}, author = {Latham, John-Paul and Munjiza, Antonio and Garcia, Xavier and Xiang, Jiansheng and Guises, Romain} } @article {LoIacono2008a, title = {{Very high-resolution seismo-acoustic imaging of seagrass meadows (Mediterranean Sea): Implications for carbon sink estimates}}, journal = {Geophysical Research Letters}, volume = {35}, number = {18}, year = {2008}, month = {sep}, pages = {L18601}, abstract = {Posidonia oceanica is a widespread coastal Mediterranean seagrass which accumulates in its subsurface large quantities of organic material derived from its roots, rhizomes and leaf sheaths embedded in sandy sediments. These organic deposits may be up to several meters thick as they accumulate over thousands of years forming the matte, whose high content in organic carbon plays a major role in the global ocean carbon cycle. In this study, very high-resolution seismo-acoustic methods were applied to image the subsurface features of a P. oceanica seagrass meadow at Portlligat (Cadaqu{\'e}s, Girona, Spain), in the NW-Mediterranean Sea. Our findings yield fresh insights into the settling of the P. oceanica meadow in the study area, and define with unprecedented detail the potential volume occupied by the matte. A strong reflector, located from 4.3 to 11.7 m depth, was recognized in several seismo-acoustic profiles as the substratum on which P. oceanica first settled in the study area. A 3D bathymetric model of this substratum allowed us to reconstruct the Portlligat palaeo-environment prior to the settling of P. oceanica, which corresponded to a shallow coastal setting protected from the open sea. A core drilled in the meadow at Portlligat revealed the presence of a 6 in thick dense matte composed of medium to coarse, sandy sediments mixed with plant debris and bioclasts. Radiocarbon datings revealed a constant accretion rate of the matte of about 1.1 m/kyr. Gravelly bioclastic deposits observed at the base of the core correspond to the base of the matte and gave a date of 5616 {\textpm} 46 Cal yr BP. For the first time, very high-resolution marine geophysical techniques allowed us to accurately define the volume occupied by P. oceanica matte, which in the study area reaches up to almost 220,000 {\textpm} 17,400 M3. This result is an important step forward in our efforts to estimate the size of the carbon sink represented by P. oceanica meadows along the Mediterranean coasts significantly contributing to the biosphere carbon cycle. Copyright 2008 by the American Geophysical Union.}, issn = {0094-8276}, doi = {10.1029/2008GL034773}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57849159443\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Mateo, Miguel Angel and Gr{\'a}cia, Eul{\`a}lia and Guasch, Lluis and Carbonell, Ram{\'o}n and Serrano, Laura and Serrano, Oscar and Da{\~n}obeitia, Juanjo} } @article {Garcia2007, title = {{Acoustic response of cemented granular sedimentary rocks: Molecular dynamics modeling}}, journal = {Physical Review E}, volume = {75}, number = {6}, year = {2007}, month = {jun}, pages = {061308}, abstract = {The effect of cementation processes on the acoustical properties of sands is studied via molecular dynamics simulation methods. We propose numerical methods where the initial uncemented sand is built by simulating the settling process of sediments. Uncemented samples of different porosity are considered by emulating natural mechanical compaction of sediments due to overburden. Cementation is considered through a particle-based model that captures the underlying physics behind the process. In our simulations, we consider samples with different degrees of compaction and cementing materials with distinct elastic properties. The microstructure of cemented sands is taken into account while adding cement at specific locations within the pores, such as grain-to-grain contacts. Results show that the acoustical properties of cemented sands are strongly dependent on the amount of cement, its stiffness relative to the hosting medium, and its location within the pores. Simulation results are in good correspondence with available experimental data and compare favorably with some theoretical predictions for the sound velocity within a range of cement saturation, porosity, and confining pressure. {\textcopyright} 2007 The American Physical Society.}, issn = {1539-3755}, doi = {10.1103/PhysRevE.75.061308}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34547305692\&partnerID=tZOtx3y1}, author = {Garcia, Xavier and Medina, Ernesto} } @article {DelaPuente2007, title = {{An arbitrary high-order discontinuous Galerkin method for elastic waves on unstructured meshes - IV. Anisotropy}}, journal = {Geophysical Journal International}, volume = {169}, number = {3}, year = {2007}, pages = {1210{\textendash}1228}, abstract = {We present a new numerical method to solve the heterogeneous elastic anisotropic wave equation with arbitrary high-order accuracy in space and time on unstructured tetrahedral meshes. Using the most general Hooke{\textquoteright}s tensor we derive the velocity-stress formulation leading to a linear hyperbolic system which accounts for the variation of the material properties depending on direction. This approach allows for the accurate modelling even of the most general crystalline symmetry class, the triclinic anisotropy, as no interpolation of material properties to particular mesh vertices is necessary. The proposed method combines the Discontinuous Galerkin method with the arbitrary high-order derivatives (ADER) time integration approach using arbitrary high-order derivatives of the piecewise polynomial representation of the unknown solution. The discontinuities of this piecewise polynomial approximation at element interfaces permit the application of the well-established theory of finite volumes and numerical fluxes across element interfaces obtained by the solution of derivative Riemann problems. Due to the novel ADER time integration technique the scheme provides the same approximation order in space and time automatically. A numerical convergence study confirms that the new scheme achieves the desired arbitrary high-order accuracy even for anisotropic material on unstructured tetrahedral meshes. Furthermore, it shows that higher accuracy can be reached with higher-order schemes while reducing computational cost and storage space. To this end, we also present a new Godunov-type numerical flux for anisotropic material and compare its accuracy with a computationally simpler Rusanov flux. As a further extension, we include the coupling of anisotropy and viscoelastic attenuation based on the Generalized Maxwell Body rheology and the mean and deviatoric stress concepts. Finally, we validate the new scheme by comparing the results of our simulations to an analytic solution as well as to spectral element computations. {\textcopyright} 2007 The Authors Journal compilation {\textcopyright} 2007 RAS.}, keywords = {ADER approach, Anisotropy, Discontinuous Galerkin method, High-order accuracy in space and time, Unstructured tetrahedral meshes}, issn = {0956540X}, doi = {10.1111/j.1365-246X.2007.03381.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34250166175\&partnerID=tZOtx3y1}, author = {de la Puente, Josep and K{\"a}ser, Martin and Dumbser, Michael and Igel, Heiner} } @article {Kaser2007, title = {{An arbitrary high-order Discontinuous Galerkin method for elastic waves on unstructured meshes - III. Viscoelastic attenuation}}, journal = {Geophysical Journal International}, volume = {168}, number = {1}, year = {2007}, month = {jan}, pages = {224{\textendash}242}, abstract = {We present a new numerical method to solve the heterogeneous anelastic, seismic wave equations with arbitrary high order accuracy in space and time on 3-D unstructured tetrahedral meshes. Using the velocity-stress formulation provides a linear hyperbolic system of equations with source terms that is completed by additional equations for the anelastic functions including the strain history of the material. These additional equations result from the rheological model of the generalized Maxwell body and permit the incorporation of realistic attenuation properties of viscoelastic material accounting for the behaviour of elastic solids and viscous fluids. The proposed method combines the Discontinuous Galerkin (DG) finite element (FE) method with the ADER approach using Arbitrary high order DERivatives for flux calculations. The DG approach, in contrast to classical FE methods, uses a piecewise polynomial approximation of the numerical solution which allows for discontinuities at element interfaces. Therefore, the well-established theory of numerical fluxes across element interfaces obtained by the solution of Riemann problems can be applied as in the finite volume framework. The main idea of the ADER time integration approach is a Taylor expansion in time in which all time derivatives are replaced by space derivatives using the so-called Cauchy-Kovalewski procedure which makes extensive use of the governing PDE. Due to the ADER time integration technique the same approximation order in space and time is achieved automatically and the method is a one-step scheme advancing the solution for one time step without intermediate stages. To this end, we introduce a new unrolled recursive algorithm for efficiently computing the Cauchy-Kovalewski procedure by making use of the sparsity of the system matrices. The numerical convergence analysis demonstrates that the new schemes provide very high order accuracy even on unstructured tetrahedral meshes while computational cost and storage space for a desired accuracy can be reduced when applying higher degree approximation polynomials. In addition, we investigate the increase in computing time, when the number of relaxation mechanisms due to the generalized Maxwell body are increased. An application to a well-acknowledged test case and comparisons with analytic and reference solutions, obtained by different well-established numerical methods, confirm the performance of the proposed method. Therefore, the development of the highly accurate ADER-DG approach for tetrahedral meshes including viscoelastic material provides a novel, flexible and efficient numerical technique to approach 3-D wave propagation problems including realistic attenuation and complex geometry. {\textcopyright} 2006 The Authors Journal compilation {\textcopyright} 2006 RAS.}, keywords = {Attenuation, Discontinuous Galerkin, High order accuracy, Relaxation, Unstructured meshes, Viscoelasticity}, issn = {0956540X}, doi = {10.1111/j.1365-246X.2006.03193.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33845968162\&partnerID=tZOtx3y1}, author = {K{\"a}ser, Martin and Dumbser, Michael and de la Puente, Josep and Igel, Heiner} } @article {Dumbser2007, title = {{Arbitrary high-order finite volume schemes for seismic wave propagation on unstructured meshes in 2D and 3D}}, journal = {Geophysical Journal International}, volume = {171}, number = {2}, year = {2007}, pages = {665{\textendash}694}, abstract = {We present a new numerical method to solve the heterogeneous anelastic seismic wave equations with arbitrary high order of accuracy in space and time on unstructured triangular and tetrahedral meshes in two and three space dimensions, respectively. Using the velocity-stress formulation provides a linear hyperbolic system of equations with source terms that is completed by additional equations for the anelastic functions including the strain history of the material. These additional equations result from the rheological model of the generalized Maxwell body and permit the incorporation of realistic attenuation properties of viscoelastic material accounting for the behaviour of elastic solids and viscous fluids. The proposed method relies on the finite volume (FV) approach where cell-averaged quantities are evolved in time by computing numerical fluxes at the element interfaces. The basic ingredient of the numerical flux function is the solution of Generalized Riemann Problems at the element interfaces according to the arbitrary high-order derivatives (ADER) approach of Toro et al., where the initial data is piecewise polynomial instead of piecewise constant as it was in the original first-order FV scheme developed by Godunov. The ADER approach automatically produces a scheme of uniformly high order of accuracy in space and time. The high-order polynomials in space, needed as input for the numerical flux function, are obtained using a reconstruction operator acting on the cell averages. This reconstruction operator uses some techniques originally developed in the Discontinuous Galerkin (DG) Finite Element framework, namely hierarchical orthogonal basis functions in a reference element. In particular, in this article we pay special attention to underline the differences as well as the points in common with the ADER-DG schemes previously developed by the authors, especially concerning the MPI parallelization of both methods. The numerical convergence analysis demonstrates that the proposed FV schemes provide very high order of accuracy even on unstructured tetrahedral meshes while computational cost for a desired accuracy can be reduced when applying higher order reconstructions. Applications to a series of well-acknowledged elastic and anelastic test cases and comparisons with analytic and numerical reference solutions, obtained by different well-established numerical methods, confirm the performance of the proposed method. Therefore, the development of the highly accurate ADER-FV approach for tetrahedral meshes including viscoelastic material provides a novel, flexible and efficient numerical technique to approach 3-D wave propagation problems including realistic attenuation and complex geometry. {\textcopyright} 2007 The Authors Journal compilation {\textcopyright} 2007 RAS.}, keywords = {ADER approach, Attenuation, Finite volume schemes, High-order accuracy, Tetrahedral meshes, Viscoelasticity}, issn = {0956540X}, doi = {10.1111/j.1365-246X.2007.03421.x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-35348851376\&partnerID=tZOtx3y1}, author = {Dumbser, Michael and K{\"a}ser, Martin and de la Puente, Josep} } @inbook {RaneroC.R.;vonHueneR.;WeinrebeW.andBarckhausen2007, title = {{Convergent margin tectonics of Middle America: A marine perspective}}, booktitle = {Central America, Geology, Hazards and Resources}, year = {2007}, pages = {239{\textendash}265}, keywords = {A. A. Balkema Publisher)., Ed. G. Alvarado and J. Bunschu}, url = {http://sfx.bibliotecas.csic.es/sfx\_local?url\_ver=Z39.88-2004\&rft\_val\_fmt=info\%3Aofi\%2Ffmt\%3Akev\%3Amtx\%3Abook\&rft.genre=bookitem\&rft.btitle=Central America\%3A Geology\%2C Resources and Hazards\&rft.spage=239\&rft.epage=265\&rft.date=2007\&rft.aulast=Ranero\&}, author = {Ranero, C. R. and von Huene, R. and Weinrebe, W. and Barckhausen, U.} } @article {Booth-Rea2007, title = {{Crustal types and Tertiary tectonic evolution of the Albor{\'a}n sea, western Mediterranean}}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {8}, number = {10}, year = {2007}, pages = {n/a{\textendash}n/a}, abstract = {Multichannel seismic reflection images across the transition between the east Albor{\'a}n and the Algero-Balearic basins show how crustal thickness decreases from about 5 s two-way traveltime (TWTT, \~{}15 km thick) in the west (east Albor{\'a}n basin) to \~{}2 s TWTT typical of oceanic crust (\~{}6 km thick) in the east (Algero-Balearic basin). We have differentiated three different crustal domains in this transition, mainly on the basis of crustal thickness and seismic signature. Boundaries between the three crustal domains are transitional and lack evidence for major faults. Tilted blocks related to extension are very scarce and all sampled basement outcrops are volcanic, suggesting a strong relationship between magmatism and crustal structure. Stratigraphic correlation of lithoseismic units with sedimentary units of southeastern Betic basins indicates that sediments onlap igneous basement approximately at 12 Ma in the eastern area and at 8 Ma in the western area. Linking seismic crustal structure with magmatic geochemical evidence suggests that the three differentiated crustal domains may represent, from west to east, thin continental crust modified by arc magmatism, magmatic-arc crust, and oceanic crust. Middle to late Miocene arc and oceanic crust formation in the east Albor{\'a}n and Algero-Balearic basins, respectively, occurred during westward migration of the Gibraltar accretionary wedge and shortening in the Betic-Rif foreland basins. Arc magmatism and associated backarc oceanic crust formation were related to early to middle Miocene subduction and rollback of the Flysch Trough oceanic basement. Subduction of this narrow slab beneath the Albor{\'a}n basin was coeval with collision of the Albor{\'a}n domain with the Iberian and African passive margins and subsequent subcontinental- lithosphere edge delamination along the Betic-Rif margins. Copyright 2007 by the American Geophysical Union.}, keywords = {Albor{\'a}n basin, Algero-Balearic basin, Crustal structure, Magmatic arc, Reflection seismics, Western Mediterranean}, issn = {15252027}, doi = {10.1029/2007GC001639}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-54349126940\&partnerID=tZOtx3y1}, author = {Booth-Rea, G. and Ranero, C. R. and Mart{\'\i}nez-Mart{\'\i}nez, J. M. and Grevemeyer, I.} } @article {Larrasoana2007, title = {{Diagenetic formation of greigite and pyrrhotite in gas hydrate marine sedimentary systems}}, journal = {Earth and Planetary Science Letters}, volume = {261}, number = {3-4}, year = {2007}, pages = {350{\textendash}366}, abstract = {Mineral magnetic results and electron microscope observations from gas hydrate-bearing marine sediments cored at southern Hydrate Ridge during Ocean Drilling Program Leg 204 (Sites 1244 to 1252, Cascadia Margin, offshore Oregon) demonstrate that authigenic greigite and pyrrhotite formed as a byproduct of microbially-mediated diagenetic reactions in the sulphate, the anaerobic oxidation of methane (AOM), and the methanic/gas hydrate zones. Geochemical conditions favourable for formation and preservation of greigite and pyrrhotite appear to be a limited source of sulphide, whether it derives from microbially-driven sulphate reduction in the sulphate zone, in the AOM zone or in deep sediments undergoing AOM, so that pyritization reactions are not driven to completion. Our results indicate that rock magnetic identification of greigite and pyrrhotite should be useful for detecting ancient gas hydrate systems in the marine sedimentary record, because it can enable rapid screening of ancient sediments for potential horizons where methane and disseminated gas hydrates might have occurred. Formation of authigenic greigite and pyrrhotite at different depths within the gas hydrate stability zone also implies that the magnetization of the host sediments will have been acquired at variable times, which is likely to compromise paleomagnetic results from greigite- and pyrrhotite-bearing marine sediments. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {anaerobic oxidation of methane, diagenesis, gas hydrate, greigite, iron sulphide, marine sediments, methane, mineral magnetism, pyrrhotite, siderite, sulphate reduction}, issn = {0012821X}, doi = {10.1016/j.epsl.2007.06.032}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34548475090\&partnerID=tZOtx3y1}, author = {Larrasoa{\~n}a, Juan C. and Roberts, Andrew P. and Musgrave, Robert J. and Gr{\'a}cia, Eul{\`a}lia and Pi{\~n}ero, Elena and Vega, Marta and Mart{\'\i}nez-Ruiz, Francisca} } @article {Ranero2007, title = {{Drilling the Seismogenic Zone of an Erosinal Convergent Margin: IODP Costa Rica Seismogenesis Project CRISP}}, journal = {Scientific Drilling}, number = {Special, No. 1}, year = {2007}, month = {nov}, pages = {51{\textendash}54}, issn = {1816-3459}, doi = {10.2204/iodp.sd.s01.29.2007}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-72749124634\&partnerID=tZOtx3y1}, author = {Ranero, Cesar R. and Vannucchi, Paola and von Huene, Roland} } @article {Loreto2007, title = {{Evidence for fluid circulation, overpressure and tectonic style along the Southern Chilean margin}}, journal = {Tectonophysics}, volume = {429}, number = {3-4}, year = {2007}, month = {jan}, pages = {183{\textendash}200}, abstract = {The southern Chilean convergent margin, between 50{\textdegree} and 57{\textdegree} S, is shaped by the interaction of the three main plates: Antarctic, South America and Scotia. North of 53{\textdegree} S, the convergence between Antarctic and South America plates is close to orthogonal to the continental margin strike. Here, the deformational style of the accretionary prism is mainly characterized by seaward-verging thrusts and locally by normal faults and fractures, a very limited lateral extension of prism, a very shallow dip (\~{} 6{\textdegree}) d{\'e}collement, and subduction of a thick and relatively undeformed trench sedimentary sequence. South of 53{\textdegree} S, convergence is oblique to the margin, locally, the trench sediments are proto-deformed by double vergence thrusting and the front of the prism grows through landward-verging thrusting. The d{\'e}collement is sub-horizontal and deep, involving most of the sediment over the oceanic crust in the accretionary process, building a comparatively wide and thicker prism. A Bottom Simulating Reflector is present across the whole prism to the abyssal plan, suggesting the presence of gas in the sediments. The analysis of P- and S-wave velocity reflectivity sections, derived by amplitude versus offset technique (AVO), detailed velocity information and the velocity-derived sediment porosity have been integrated with the structural analysis of the accretionary prism of two selected pre-stack depth migrated seismic lines, aiming to explain the relation between fluid circulation and tectonics. Accretion along double vergence thrust faults may be associated with the presence of overpressured fluid, which decreases the effective shear stress coefficient along the main d{\'e}collement and within the sediments, and modify the rheolgical properties of rocks. The presence of an adequate drainage network, represented by interconnected faults and fractures affecting the entire sedimentary sequence, can favour the escape of pore fluid toward the sea bottom, while, less permeable and not faulted sediments can favour fluid accumulations. Gravitational and tectonic dewatering, and stratigraphy could control the consolidation and the pore overpressure of sediments involved in subduction along the trench. The results of our analysis suggest the existence of a feedback between tectonic style and fluid circulation. {\textcopyright} 2006 Elsevier B.V. All rights reserved.}, keywords = {Accretion, AVO, Back-thrust, Dewatering, Overpressure, subduction}, issn = {00401951}, doi = {10.1016/j.tecto.2006.09.016}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33845522651\&partnerID=tZOtx3y1}, author = {Loreto, Maria Filomena and Tinivella, Umberta and Ranero, Cesar R.} } @article {Pinero2007, title = {{Gas hydrate disturbance fabrics of southern Hydrate Ridge sediments (ODP Leg 204): Relationship with texture and physical properties}}, journal = {Geo-Marine Letters}, volume = {27}, number = {2-4}, year = {2007}, pages = {279{\textendash}288}, abstract = {Soupy and mousse-like fabrics are disturbance sedimentary features that result from the dissociation of gas hydrate, a process that releases water. During the core retrieval process, soupy and mousse-like fabrics are produced in the gas hydrate-bearing sediments due to changes in pressure and temperature conditions. Therefore, the identification of soupy and mousse-like fabrics can be used as a proxy for the presence of gas hydrate in addition to other evidence, such as pore water freshening or anomalously cool temperature. We present here grain-size results, mineralogical composition and magnetic susceptibility data of soupy and mousse-like samples from the southern Hydrate Ridge (Cascadia accretionary complex) acquired during Leg 204 of the Ocean Drilling Program. In order to study the relationship between sedimentary texture and the presence of gas hydrates, we have compared these results with the main textural and compositional data available from the same area. Most of the disturbed analyzed samples from the summit and the western flank of southern Hydrate Ridge show a mean grain size coarser than the average mean grain size of the hemipelagic samples from the same area. The depositional features of the sediments are not recognised due to disturbance. However, their granulometric statistical parameters and distribution curves, and magnetic susceptibility logs indicate that they correspond to a turbidite facies. These results suggest that gas hydrates in the southern Hydrate Ridge could form preferentially in coarser grain-size layers that could act as conduits feeding gas from below the BSR. Two samples from the uppermost metres near the seafloor at the summit of the southern Hydrate Ridge show a finer mean grain-size value than the average of hemipelagic samples. They were located where the highest amount of gas hydrates was detected, suggesting that in this area the availability of methane gas was high enough to generate gas hydrates, even within low-permeability layers. The mineralogical composition of the soupy and mousse-like sediments does not show any specific characteristic with respect to the other samples from the southern Hydrate Ridge. {\textcopyright} Springer-Verlag 2007.}, issn = {0276-0460}, doi = {10.1007/s00367-007-0077-z}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34250188050\&partnerID=tZOtx3y1}, author = {Pi{\~n}ero, Elena and Gr{\'a}cia, Eul{\`a}lia and Mart{\'\i}nez-Ruiz, Francisca and Larrasoa{\~n}a, Juan Cruz and Vizcaino, Alexis and Ercilla, Gemma} } @booklet {McIntosh2007, title = {{The Nicaragua Convergent Margin: Seismic Reflection Imaging of the Source of a Tsunami Earthquake}}, journal = {The seismogenic zone of subduction thrust faults}, year = {2007}, pages = {257{\textendash}287}, publisher = {University of British Columbia Press}, abstract = {Peer Reviewed}, isbn = {isbn: 978-0-231-13866-6}, url = {http://digital.csic.es/handle/10261/108405}, author = {McIntosh, Kirk D and Silver, Eli a and Ahmed, Imtiaz and Berhorst, Arnim and Ranero, C{\'e}sar R and Kelly, Robyn K and Flueh, Ernst R} } @article {Grevemeyer2007, title = {{Passive and active seismological study of bending-related faulting and mantle serpentinization at the Middle America trench}}, journal = {Earth and Planetary Science Letters}, volume = {258}, number = {3-4}, year = {2007}, month = {jun}, pages = {528{\textendash}542}, abstract = {Water transported within the subducting oceanic lithosphere into the Earth{\textquoteright}s interior affects a wealth of subduction zone processes, including intraslab earthquakes and arc magmatism. In recent years growing evidence suggests that much of the hydration of oceanic plates occurs at the trench-ocean slope right before subduction. Here, normal faults are created while the rigid lithosphere bends into the trench. Offshore of Middle America, multi-channel seismic reflection imaging suggests that bending-related faults cut into the uppermost mantle, providing a mechanism for hydration and transformation of mantle peridotites into serpentinites. Seismic wide-angle reflection and refraction data were collected coincident with one of the seismic profiles where the faults have been imaged. Travel time inversion provides evidence that both crustal and uppermost mantle velocities are reduced with respect to the velocity structure found in mature oceanic crust away from deep-sea trenches. If mantle velocity reduction is solely produced by hydration, velocities indicate 10-15\% of serpentinization in the uppermost 3~km of the mantle, where seismic data provide enough resolution. A small network of ocean bottom hydrophones, deployed for about a month, detected \~{} 3 local micro earthquakes per day. Earthquake epicentres align with fault scarps at the seafloor and continuous earthquake activity might be an important process to facilitate the percolation of seawater into the upper mantle. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {bending-related normal faulting, earthquakes, global water cycle, seismic refraction, serpentinization, subduction}, issn = {0012821X}, doi = {10.1016/j.epsl.2007.04.013}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34249911517\&partnerID=tZOtx3y1}, author = {Grevemeyer, Ingo and Ranero, Cesar R. and Flueh, Ernst R. and Kl{\"a}schen, Dirk and Bialas, J{\"o}rg} } @article {Goldfinger2007, title = {{Rupture lengths and temporal history of significant earthquakes on the offshore and north coast segments of the Northern San Andreas Fault based on turbidite stratigraphy}}, journal = {Earth and Planetary Science Letters}, volume = {254}, number = {1-2}, year = {2007}, pages = {9{\textendash}27}, abstract = {74 piston, gravity and jumbo Kasten cores were collected from channel and canyon systems draining the northern California continental margin to investigate the record of periodic Holocene turbidites for possible connection to large magnitude earthquakes on the adjacent Northern San Andreas Fault. Poorly known channel systems were mapped with multibeam sonar to define pathways and channel confluences. Cores sampled all major and many minor channel systems extending from Cape Mendocino to just north of Monterey Bay. Sampling both along and across channels was done and particular attention was paid to channel confluences, as these areas afford opportunities to test for synchronous triggering of turbidity currents. While at sea, all cores were scanned using a GEOTEK multisensor core logger (MSCL), which collects high-resolution photography, P-wave velocity, gamma-ray density, and magnetic susceptibility data from the unsplit cores. Lithology was logged visually, and cores were later imaged with X-radiography. We use 14C ages, relative dating tests at channel confluences, and stratigraphic correlation using physical properties to determine whether turbidites deposited in separate channel systems are correlative, implying they were triggered by a common event. These tests can, in most cases, separate earthquake-triggered turbidity currents from other possible sources. The late Holocene turbidite record off northern California passes these tests for synchronous triggering, and can be correlated with multiple proxies from site to site between Noyo Channel and the latitude of San Francisco. Preliminary comparisons of our event ages with existing and in progress work at onshore coastal sites show good correlation, further circumstantial evidence that the offshore record is primarily earthquake generated. During the last \~{} 2800~yr, 15 turbidites are recognized, including the great 1906 earthquake. Their chronology establishes an average repeat time of \~{} 200~yr, similar to the onshore value of \~{} 230~yr. Along-strike correlation suggests that at least 8 of the youngest 10 of these events ruptured the 320~km distance from the Mendocino Triple Junction to near San Francisco. {\textcopyright} 2006.}, keywords = {Northern San Andreas Fault, Paleoseismology, Turbidite}, issn = {0012821X}, doi = {10.1016/j.epsl.2006.11.017}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33846271439\&partnerID=tZOtx3y1}, author = {Goldfinger, Chris and Morey, Ann E. and Nelson, C. Hans and Guti{\'e}rrez-Pastor, Julia and Johnson, Joel E. and Karabanov, Eugene and Chaytor, Jason and Eriksson, Andrew} } @conference {Urgeles2007, title = {{Scientific Ocean Drilling Behind the Assessment of Geo-hazards from Submarine Slides}}, booktitle = {Eos}, volume = {88}, number = {17}, year = {2007}, pages = {192}, issn = {00963941}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34249827905\&partnerID=tZOtx3y1}, author = {Urgeles, Roger and Camerlenghi, Angelo and Ercilla, Gemma and Anselmetti, Flavio and Br{\"u}ckmann, Warner and Canals, Miquel and Gr{\'a}cia, Eul{\`a}lia and Locat, Jacques and Krastel, Sebastian and Solheim, Anders} } @article {Biescas2007, title = {{Seismic attenuation of coda waves in the eastern region of Cuba}}, journal = {Tectonophysics}, volume = {429}, number = {1-2}, year = {2007}, pages = {99{\textendash}109}, publisher = {Elsevier}, abstract = {11 pages, 8 figures, 2 tables}, keywords = {coda wave, Cuba, quality factor Q, Seismic attenuation}, issn = {00401951}, doi = {10.1016/j.tecto.2006.09.013}, url = {http://digital.csic.es/handle/10261/26812}, author = {Biescas, Berta and Rivera, Zulima and Zapata, Jose Alejandro} } @book {Sallares2007, title = {{Special Paper 430: Plates, Plumes and Planetary Processes}}, series = {Special Paper of the Geological Society of America}, volume = {430}, year = {2007}, pages = {507{\textendash}524}, publisher = {Geological Society of America}, organization = {Geological Society of America}, abstract = {At present there is no single "unified theory" capable of explaining the variety of geological, geophysical, and geochemical observations that characterize what is generically known as hotspot magmatism. An increasing number of geophysical and geo- chemical observations disagree with the predictions of the conventional thermal plume model, in which excess melting is due mainly to high mantle temperatures. Other parameters such as the presence of water or the composition of the mantle source have been shown to be as important as temperature in controlling the structure and physical properties of the igneous crust. In this article we first emphasize the importance of doing proper velocity and density modeling, including comprehensive uncertainty analysis, to determine how well resolved the geophysical parameters actually are. We show that in some cases the contribution of velocity-derived lateral crustal density variations can be sufficiently significant to account for the observed gravity and topography anomalies without calling for noticeable mantle density contrasts. Next we show that the comparison of crustal geometry obtained along age-progressive volcanic tracks enables temporal variations of the hotspot-ridge distance to be estimated. Finally we use a 2-D mantle melting model to illustrate the effect of different mantle melting parameters on the resulting crustal structure. The tests made indicate that it is difficult to find a plausible combination of mantle temperature, upwelling rate, melt productivity, and thickness of the melting zone to explain either the high-velocity, un- derplated bodies frequently described at midplate settings or the lack of a positive crustal thickness-velocity (H-Vp) correlation found at igneous provinces originated on-ridge. We suggest that the main parameter controlling the generation of volcanic underplating is the presence of a lithospheric lid limiting the extent of the mantle melting zone, whereas the H-Vp anticorrelation can be related to the presence of a major element heterogeneity, such as eclogite derived from recycled oceanic lithosphere, in the mantle source. {\textcopyright} 2007 The Geological Society of America.}, keywords = {Crustal structure, Density, Mantle melting parameters, Seismic velocity}, isbn = {978-0-8137-2430-0}, issn = {00721077}, doi = {10.1130/978-0-8137-2430-0}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-75749138216\&partnerID=tZOtx3y1}, author = {Sallares, Valenti and Calahorrano, Alcinoe} }