@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 {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} } @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.} } @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 {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.} } @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.} } @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 {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.} } @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.} }