Eric Grossman Patrick E. Hart Michael E. Field Peter Triezenberg 2006 seismic reflection profile section U.S. Geological Survey Open-File Report 2006-1247 Menlo Park, CA U.S. Geological Survey <http://pubs.usgs.gov/of/2006/1247/> This report consists of high-resolution chirp seismic reflection profile data from the northern Gulf of Lions, Spain. These data were acquired in 2004 using the Research Vessel Oceanus (USGS Cruise ID: O-1-04-MS). The data are available in binary and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser. Marine seismic reflection data are used to image and map sedimentary and structural features of the seafloor and subsurface. These data were acquired across the shelf and canyon area of the Gulf of Lions, Spain as part of a multinational effort to characterize the geologic framework and sedimentary environment of the region. The specific objective of this seismic survey is to provide seismic reflection images of the depositional geometry of the upper 50 meters of subbottom stratigraphy in order to better understand the mechanisms of sediment transport and deposition. These chirp seismic profiles provide high-quality images with approximately 20 cm of vertical resolution and up to 80 m of subbottom penetration. Chirp seismic reflection profiles are acquired by means of an acoustic source and a hydrophone array, both contained in a single unit towed in the water behind a survey vessel. The sound source emits a short (30 ms) swept-frequency (500 to 7200 Hz)acoustic pulse, which propagates through the water and sediment columns. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor), and detected by the hydrophone array, and digitally recorded by the onboard PC-based acquisition system. As the vessel moves, this process is repeated multiple times per second, producing a two-dimensional image of the shallow geologic structure beneath the ship track. Additional information about the USGS survey O-1-04-MS is available at <http://walrus.wr.usgs.gov/infobank/o/o104ms/html/o-1-04-ms.meta.html>. 20030925 20031001 Data assumed to be constant over time, but the imaged geology may change due to geologic processes. Complete None planned 3.1808 3.4586 42.4418 42.1763 General U.S. Geological Survey USGS Coastal and Marine Geology Program CMGP EuroSTRATAFORM Seismic Reflection Sedimentation ISO 19115 Topic Category geoscientificinformation imageryBaseMapsEarthCover oceans General Cap de Creus Shelf Cap de Creus Canyon Gulf of Lions Spain Geographic Names Information System (GNIS) Mediterranean Sea None. These data are held in the public domain. The U.S. Geological Survey requests to be acknowledged as the originator of the data in future products or derivative research. Eric Grossman U.S. Geological Survey Geologist mailing address

400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA 831-427-4725 egrossman@usgs.gov <http://pubs.usgs.gov/of/2006/1247/images/gol_coverage_area.png> Map of Gulf of Lions showing areas of 2004 USGS chirp seismic refleciton research cruise PNG Alonso, B. Canals, M. Got, H. Maldonado, A. 1991 American Association of Petroleum Geologists Bulletin 75, p. 1195-1214 Tulsa, OK American Association of Petroleum Geologists Baztan, J. Berné, S., Olivet, J.-L Rabineau, M. Aslanian, D. Gaudin, M. Réhault, J.P. Canals, M. 2005 Marine and Petroleum Geology 22, n. 6-7, p. 805-826 Guildford, Surrey, England Butterworth Scientific Ltd. Berné, S. Carré, D. Loubrieu, B. Mazé, J.-P. Normand, A. 2001 Brest, France Ifremer, Brest Berné, S. Gorini, C. 2005 Marine and Petroleum Geology 22, n. 6-7, p. 691-693 Guildford, Surrey, England Butterworth Scientific Ltd. Berné, S. Carré, B. Loubrieu, B. Mazé, J.P. Morvan, L. Normand, A. 2004 Brest, France Ifremer, Brest Berné, S. Loubrieu, B. The Calmar scientific party 1999 First results of the Calmar cruise. Comptes Rendus de l'Académie des Sciences de Paris 328: 471-477 Paris l'Académie des Sciences de Paris Berné, S. Loubrieu, B. l’équipe embarquée CALMAR 1997 Brest, France Ifremer, Brest Correggiari, A. Trincardi, F. Langone, L. Roveri, M. 2001 Journal of Sedimentary Geology 71, p. 218-236 Tulsa, OK SEPM (Society for Sedimentary Geology) Grossman, E.E. Hart, P. Field, M.E. 2005 EuroSTRATAFORM - Promess Joint Meeting, Salamanca, Spain, October 24-27, 2005 October 24-27, 2005 <http://www.soc.soton.ac.uk/CHD/EUROSTRATAFORM/salamanca2005/index.html> Lofi, J. Rabineau, M. Gorini, C. Berne, S. Clauzon, G. De Clarens, P. Tadeu Dos Reis, A. Mountain, G.S. Ryan, W.B.F. Steckler, M.S. Fouchet, C. 2003 Marine Geology 198(3-4): 289-317 Amsterdam Elsevier Scientific Pub. Co Marsset, T. Bellec, V. 2002 Sedimentology 49, p. 255-276 Blackwell Scientific Publishers Oxford, Boston Rabineau, M. Berné, S. Le Drezen, E. Lericolais, G. Rutunno, M. 1998 Marine Petroleum Geology 15, p. 439-452 Guildford, Surrey, England Butterworth Scientific Ltd. Rabineau, M. Berné, S. Aslanian, D. Olivet, J.-L. Phillipe, J. Guillocheau, F. Bourillet, J.-F. Ledrezen, E. Granjeon, D. 2005 Marine and Petroleum Geology 22, n. 607, p. 775-804 Guildford, Surrey, England Butterworth Scientific Ltd. Schoolmeester, T. Grossman, E.E. García-García, A. Canals, M. Field, M. Levey, M. Fabres, J. Orange, D. 2005 EuroSTRATAFORM - Promess Joint Meeting, Salamanca, Spain, October 24-27, 2005 October 24-27, 2005 <http://www.soc.soton.ac.uk/CHD/EUROSTRATAFORM/salamanca2005/index.html> Torres, J. Savoye, B. Cochonat, P. 1995 Journal of Sedimentary Research 65, p. 368-38 Tulsa, OK SEPM (Society for Sedimentary Geology) The validity or accuracy of marine seismic reflection profiles is highly qualitative, and depends on equipment and operating condition variables too numerous to quantify. There have been no efforts to assess the validity of the data. These data have not been assessed for internal consistency. These are sparse line coverages (2D). Therefore, data are inherently incomplete. Geologic details between lines must be inferred. The surveys were not designed to cover a particular geographic area; the line spacings and azimuths were chosen to assess the regional stratigraphy. Positions were determined with differential Global Positioning System (GPS). Absolute position accuracy was approximately plus/minus 10 m. The vertical position was local sea level and there have been no corrections to a datum or for tidal variations. Single-channel chirp seismic reflection data were acquired using an Edgetech 512i subbottom profiling system. This "fish " was towed aft of the research vessel at a depth of approximately 15 meters at a ship speed of approximately 4 knots. A 30 ms swept-frequency (500 to 7200 Hz)"chirp" source signal was emitted 1 to 4 times per second depending on water depth and the returning reflections were detected by hydrophones located along the bottom of the fish. The data were digitally recorded by an on-board PC-based Delph Seismic recording system. Differential GPS position fixes were written into the seismic data trace headers and are also available in an ASCII text file. 2004 Open File preparation: The seismic profiles were converted from Delph Seimic proprietary format to standard SEG-Y format and to CGM plot files using Paradigm Focus software. Then the CGM files were converted to 300 dots per inch JPEG image file using Larson CGM to Image software. The SEG-Y data files and the JPEG image files are available for download from this on-line report. 2004 Patrick E. Hart U.S. Geological Survey Geophysicist mailing address

345 Middlefield Road Mail Stop 999

Menlo Park CA 94025-3561 USA 650-329-5160 hart@usgs.gov Horizontal X and Y locations for the seimic profiles location are provided in ASCII position files and are alos stored in the SEG-Y data trace headers in the standard header locations. 0.00001 0.00001 decimal degrees WGS 84 WGS 84 6378137 m 298.257 Binary data file: Each profile is available as a binary file in Society of Exploration Geophysicists SEG-Y format. A SEG-Y file consists of 1) a 3200-byte file identification record of EBCDIC encoded general information; 2) a 400-byte binary record with information such as sample rate and record length specific to the data set; and 3) multiple records, one seismic reflection trace per record. Each trace record is preceded by a 240-byte "trace header" containing information such as trace number and acquisition day and time specific to each trace. The trace data are represented as a time series of unitless 16-bit integer or 32-bit real numbers proportional to the pressure recorded at each hydrophone. The SEG-Y file is useful only if you have access to specialized software designed to process and display seismic reflection data. Graphic image file: Each profile is available as a JPEG image. Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, n. 2, p. 344 - 352. Also available online at: <http://www.seg.org/publications/tech-stand/> Eric Grossman U.S. Geological Survey Geologist mailing address

USGS, 400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA 831-427-4725 egrossman@usgs.gov Data may be available off-line only by special arrangement with the distributor above. Please use the on-line download option unless precluded by download times or access difficulties. U.S. Geological Suvey Open-File Report 2006-1247 This dataset was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for information, apparatus, products, or processes disclosed in this report, nor represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Although all data published in this report have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data. SEG-Y, JPEG, ASCII 2.5 gigabytes <http://pubs.usgs.gov/of/2006/1247/> CD-R or DVD-R ISO 9660 none Use of SEG-Y data requires specialized software, such as ProMax and Seisworks by Landmark Geophysical; FOCUS and SeisX by Paradigm Geophysical; SPW by Parallel Geoscience; or VISTA by Seismic Image Software. 20060728 Eric Grossman U.S. Geological Survey Geologist mailing address

USGS, 400 Natural Bridges Drive

Santa Cruz CA 95060-5792 USA 831-427-4725 egrossman@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998