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www.sea-technology.com October 2015 / st 29 For MCS data acquisition, we used an airgun array as a seismic source, with a four-airgun string, totaling 12 BOLT guns towed at 8-m depth, re- corded with a 6.0-km streamer at 12.5-m group distance (468 channels) towed at 10-m depth. We completed 27,000 airgun shots, one every 50 m. Before and after the MCS survey, one South and six North wide-angle profles were acquired. For this part of the experiment, the source employed was variable, made up of 11 to 15 BOLT airguns (6,800 or 8,000 cu. in.), rich in low frequency, towed at 15-m depth and fred every 120 s. The airgun shots generated by the vessel were re- corded by 16 ocean bottom seismom- eters (OBS) along different profles, mostly coincident with the MCS data. Concurrently with the seismic sur- vey, approximately 5,438-km swath bathymetry, acoustic backscatter, sub- bottom profler, gravity and magnet- ics data were collected, providing complementary information of the seafoor morphology, subseafoor de- formation and crustal structure. To ac- curately measure water velocity, one XBT (expendable bathythermograph) per day was launched during the sur- vey, whose values were integrated into the echosounder acquisition program. Conclusion The TSUJAL project was conducted as a result of the fruitful collaboration between NERC and CSIC, leading to the acquisition of new geophysical data. TSUJAL data processing is ongo- ing, with the frst MCS processed data showing a rather high quality, therefore promising to defne the structure of the crust in different areas of the Mexican margin. In addition to MCS data, seafoor and subseafoor information from mul- tibeam and parametric echosounder images allow identifying and charac- terizing mass transport deposits and submarine landslides associated with active faults, emphasizing the ones that can generate earthquakes and tsu- namis. Future analysis, modeling and interpretation of seismic data provided by wide-angle data at sea (via 16 OBS) and onshore (via 100 portable seismic stations) will allow resolving the ve- locity/depth structure and geometry of the Rivera oceanic crust subducting beneath the NA Plate along the active margin of Mexico at various locations. The TSUJAL cruise was carried out thanks to a barter exchange agreement within OFEG, a forum of Europe's leading oceanographic research orga- nizations for a global- and ocean-class research feet. By using bartering, the geographical location of OFEG ships can be linked to science requirements, thus increasing research effciency and saving time and money for the whole OFEG feet. This open exchange pro- vides scientists with the opportunity to access larger geographical areas and state-of-the-art equipment, thus im- proving the quality of science. Acknowledgments This research was supported by the TSUJAL project (Ref. CGL2011- 29474-C02-01), funded by the Spanish National Agency; by Mexico through CONACYT–FOMIXJAL projects 2008– 96567 (2009), 2008 –96539 (2009), 2010 –149245 (2011), 2012-08- 189963; and by partial funding from DGAPA grant #IN115513-3. This work could not have been possible without the aid of the technical staff at UTM- CSIC, especially Jose Luis Alonso and Arturo Castellon; NERC, especially Co- lin Day; Mexican institutions, especial- ly F. Nuñez-Cornú and W. Bandy; and the crews of RSS James Cook, AMR Holzinger (SEMAR, Mexico) and BO El Puma. The Ramon y Cajal program also contributed fnancial support. This work was carried out within the Grup de Recerca de la Generalitat de Cata- lunya B-CSI (2014 SGR 940). ST Dr. Rafael Bartolome has worked at CSIC for the past nine years, conduct- ing geophysical research on continental margins and acquiring and pro- cessing seismic data. He is also currently working at ICM (Instituto de Cien- cias del Mar) on a Ramon y Cajal contract. Dr. Juanjo Dañobeitia is a professor of marine geo- physics at CSIC. He was a former director and man- ager of oceanographic vessels at CSIC, and has experience in marine acoustics and seismicity, leading research and de- velopment projects on continental margins. Dr. Diego Cordoba is a professor at the Univer- sidad Complutense of Madrid. Cordoba's re- search interests include the Earth´s interior, focus- ing on the lithospheric structure. info@edgetech.com USA 1.508.291.0057 Clearly Superior Imaging SONAR SYSTEMS SUB-BOTTOM PROFILERS BATHYMETRY SYSTEMS SIDE SCAN SONARS The Leader in Underwater Technology