@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 {Bartolome2010, title = {{Imaging the Seismic Crustal Structure of the Western Mexican Margin between 19{\textdegree}N and 21{\textdegree}N}}, journal = {Pure and Applied Geophysics}, volume = {168}, number = {8-9}, year = {2010}, month = {nov}, pages = {1373{\textendash}1389}, publisher = {Birkhauser Verlag AG}, abstract = {Three thousand kilometres of multichannel (MCS) and wide-angle seismic profiles, gravity and magnetic, multibeam bathymetry and backscatter data were recorded in the offshore area of the west coast of Mexico and the Gulf of California during the spring 1996 (CORTES survey). The seismic images obtained off Puerto Vallarta, Mexico, in the Jalisco subduction zone extend from the oceanic domain up to the continental shelf, and significantly improve the knowledge of the internal crustal structure of the subduction zone between the Rivera and North American (NA) Plates. Analyzing the crustal images, we differentiate: (1) An oceanic domain with an important variation in sediment thickness ranging from 2.5 to 1 km southwards; (2) an accretionary prism comprised of highly deformed sediments, extending for a maximum width of 15 km; (3) a deformed forearc basin domain which is 25 km wide in the northern section, and is not seen towards the south where the continental slope connects directly with the accretionary prism and trench, thus suggesting a different deformational process; and (4) a continental domain consisting of a continental slope and a mid slope terrace, with a bottom simulating reflector (BSR) identified in the first second of the MCS profiles. The existence of a developed accretionary prism suggests a subduction-accretion type tectonic regime. Detailed analysis of the seismic reflection data in the oceanic domain reveals high amplitude reflections at around 6 s [two way travel time (twtt)] that clearly define the subduction plane. At 2 s (twtt) depth we identify a strong reflection which we interpret as the Moho discontinuity. We have measured a mean dip angle of 7{\textdegree} {\textpm} 1{\textdegree} at the subduction zone where the Rivera Plate begins to subduct, with the dip angle gently increasing towards the south. The oceanic crust has a mean crustal thickness of 6.0-6.5 km. We also find evidence indicating that the Rivera Plate possibly subducts at very low angles beneath the Tres Marias Islands. {\textcopyright} 2010 Springer Basel AG.}, keywords = {BSR, Crustal structure, Middle America Trench, Rivera Plate, Seismic imaging, Subduction plate}, issn = {0033-4553}, doi = {10.1007/s00024-010-0206-x}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905116997\&partnerID=tZOtx3y1}, author = {Bartolom{\'e}, Rafael and Da{\~n}obeitia, Juanjo and Michaud, Fran{\c c}ois and C{\'o}rdoba, Diego and Delgado-Argote, Luis A.} } @article {LoIacono2008, title = {{Seafloor characterization and backscatter variability of the Almer{\'\i}a Margin (Alboran Sea, SW Mediterranean) based on high-resolution acoustic data}}, journal = {Marine Geology}, volume = {250}, number = {1-2}, year = {2008}, month = {apr}, pages = {1{\textendash}18}, abstract = {An acoustic study of the Almer{\'\i}a Margin (eastern Alboran Sea, SW Mediterranean) was carried out by means of an integrated dataset, comprising deep-towed TOBI sidescan sonar, swath-bathymetry, TOPAS high-resolution seismics and sediment gravity cores. The Almer{\'\i}a Margin is a complex system dominated by volcanic and tectonic features shaped by recent sedimentary processes, in which a regional hemipelagic sedimentation is intercalated by sporadic gravitative events. The aim of this work is twofold. The first objective is to recognize the sedimentary and tectonic features that shape the Almeria Margin. The main morpho-sedimentary and morpho-structural elements observed are: the Almer{\'\i}a canyon/channel Turbidite System, the Dal{\'\i}as Tributary Valley System, landslides, active faults and folds and volcanic banks. The second aim is to explore and quantify the surface and subsurface seafloor parameters that characterize the backscatter of the study area. Sedimentary, geomorphological and biological elements that play a role in the acoustic signature of the Almer{\'\i}a Margin were detected. Nevertheless, it should be noted that seafloor acoustic backscatter is also affected by geometrical and instrumental factors. Despite the wide variability of the environments studied, a low average acoustic backscatter reflects a diffused draping of hemipelagic sedimentation in the area. Higher backscatter values were observed at the top of some volcanic banks, along the Almer{\'\i}a canyon, and in the shallower sector of the Dal{\'\i}as tributary valley system. The influence of subseafloor properties in the acoustic signature of the area was revealed by backscatter-grain size correlations, which were carried out for different depth intervals in sediment cores collected in the Almer{\'\i}a Turbidite System. A poor relationship was found between backscatter and superficial silty sediments of the area, whereas a higher correlation resulted in the upper 50~cm. The presence of subsurface turbidites in the cores associated with the higher backscatter values suggests volume interface scattering of these sandy layers as a controlling factor of the acoustic signature obtained in the Almer{\'\i}a Margin. On the other hand, in rough settings such as the ones observed in the Dal{\'\i}as Tributary Valley System, topographic relief of up to 1-1.5~m strongly interacted with the TOBI acoustic pulse. This suggests that large-scale roughness is an additional parameter that characterizes the acoustic strength of the area. Extremely high reflective patches distributed along some of the volcanic banks (Chella and Pollux Banks) for depths ranging from 230 to 470~m coincide with areas where carbonate cold water coral mounds develop. In the TOBI images, coral facies reach the maximum value of acoustic backscatter, which is probably related to the rough morphology of coral ecosystems. The position of coral mounds in the banks suggests that the occurrence of strong bottom currents and reduced sedimentary inputs are environmental factors that favour their settling and development in the Almer{\'\i}a Margin. {\textcopyright} 2007 Elsevier B.V. All rights reserved.}, keywords = {backscatter, coral mounds, deep-towed sidescan sonar TOBI, high-resolution seismics, Mediterranean Sea, South Iberian Margin, swath-bathymetry}, issn = {00253227}, doi = {10.1016/j.margeo.2007.11.004}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-41349119993\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Gr{\'a}cia, Eul{\`a}lia and Diez, Susana and Bozzano, Graziella and Moreno, Ximena and Da{\~n}obeitia, Juanjo and Alonso, Bel{\'e}n} } @article {LoIacono2008a, title = {{Very high-resolution seismo-acoustic imaging of seagrass meadows (Mediterranean Sea): Implications for carbon sink estimates}}, journal = {Geophysical Research Letters}, volume = {35}, number = {18}, year = {2008}, month = {sep}, pages = {L18601}, abstract = {Posidonia oceanica is a widespread coastal Mediterranean seagrass which accumulates in its subsurface large quantities of organic material derived from its roots, rhizomes and leaf sheaths embedded in sandy sediments. These organic deposits may be up to several meters thick as they accumulate over thousands of years forming the matte, whose high content in organic carbon plays a major role in the global ocean carbon cycle. In this study, very high-resolution seismo-acoustic methods were applied to image the subsurface features of a P. oceanica seagrass meadow at Portlligat (Cadaqu{\'e}s, Girona, Spain), in the NW-Mediterranean Sea. Our findings yield fresh insights into the settling of the P. oceanica meadow in the study area, and define with unprecedented detail the potential volume occupied by the matte. A strong reflector, located from 4.3 to 11.7 m depth, was recognized in several seismo-acoustic profiles as the substratum on which P. oceanica first settled in the study area. A 3D bathymetric model of this substratum allowed us to reconstruct the Portlligat palaeo-environment prior to the settling of P. oceanica, which corresponded to a shallow coastal setting protected from the open sea. A core drilled in the meadow at Portlligat revealed the presence of a 6 in thick dense matte composed of medium to coarse, sandy sediments mixed with plant debris and bioclasts. Radiocarbon datings revealed a constant accretion rate of the matte of about 1.1 m/kyr. Gravelly bioclastic deposits observed at the base of the core correspond to the base of the matte and gave a date of 5616 {\textpm} 46 Cal yr BP. For the first time, very high-resolution marine geophysical techniques allowed us to accurately define the volume occupied by P. oceanica matte, which in the study area reaches up to almost 220,000 {\textpm} 17,400 M3. This result is an important step forward in our efforts to estimate the size of the carbon sink represented by P. oceanica meadows along the Mediterranean coasts significantly contributing to the biosphere carbon cycle. Copyright 2008 by the American Geophysical Union.}, issn = {0094-8276}, doi = {10.1029/2008GL034773}, url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57849159443\&partnerID=tZOtx3y1}, author = {Lo Iacono, Claudio and Mateo, Miguel Angel and Gr{\'a}cia, Eul{\`a}lia and Guasch, Lluis and Carbonell, Ram{\'o}n and Serrano, Laura and Serrano, Oscar and Da{\~n}obeitia, Juanjo} }