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