@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 {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}
}
@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}
}
@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 {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 {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}
}
@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}
}
