Ray W. Sliter, Peter J. Triezenberg, Patrick E. Hart, Amy E. Draut, William R. Normark, and James E. Conrad 2008 seismic reflection profile section U.S. Geological Survey Open-File Report 2008-1246 Menlo Park, CA U.S. Geological Survey http://pubs.usgs.gov/of/2008/1246/ This report consists of high-resolution chirp and single-channel Sparker seismic-reflection- profile data from the Santa Barbara Channel, California. These data were acquired in 2007 using the Research Vessel Zephyr2 (USGS Cruise ID: Z-3-07-SC) and the Research Vessel Parke Snavely (USGS Cruise ID: S-7-08-SC). The data are available in binary, TIFF 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 northern shelf area of the Santa Barbara Channel, Calif., as part of a multiagency 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 m of subbottom stratigraphy in order to better understand the mechanisms of sediment transport and deposition. These 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 approximately 4 meters below the water surface. The sound source emits a short (30 ms) swept-frequency (500 to 7,200 Hz) acoustic pulse, which propagates through the water and sediment columns. The acoustic energy is reflected at density boundaries (such as the sea floor or sediment layers beneath the sea floor), 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. Mini-sparker profiles are collected with a 500 Joule sparker source and 15-m single-channel streamer towed at the sea surface and using the same acquisition system. Additional information about the USGS survey Z-3-07-SC is available at <http://walrus.wr.usgs.gov/infobank/z/z307sc/html/z-3-07-sc.meta.html>. Additional information about the USGS survey S-7-08-SC is available at <http://walrus.wr.usgs.gov/infobank/s/s708sc/html/s-7-08-sc.meta.html>. 20070912 20080701 ground condition Complete None planned -120.2113 -119.0521 34.4701 34.0161 ISO 19115 Topic Category geoscientificinformation oceans USGS CMG InfoBank Marine Geology Marine Geophysics Marine Seismic Geographic Names Information System (GNIS) Santa Barbara Channel Mugu Canyon Hueneme Canyon USGS CMG InfoBank CA Channel Islands National Marine Sanctuary, CA Mugu Submarine Canyon Hueneme Submarine Canyon North Pacific Ocean Northern Pacific Ocean Southern California California State Waters USA Physical materials are under controlled on-site access. If available, access to physical samples is described in the "WR CMG Sample Distribution Policy" at: http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html Please recognize the U.S. Geological Survey (USGS) as the source of this information. Physical materials are under controlled on-site access. Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user. This information is not intended for navigational purposes. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Ray W. Sliter Geophysicist mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5194 (650) 329-5190 rsliter@usgs.gov <http://pubs.usgs.gov/of/2008/1246/data/jpg/HC-01.jpg> Example of single-channel chirp seismic data accessible via this report. JPEG <http://pubs.usgs.gov/of/2008/1246/data/tif/HC-01.tif> Example of single-channel chirp seismic data accessible via this report. TIFF SEG-Y U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) 2008 Updated daily http://walrus.wr.usgs.gov/infobank/z/z307sc/html/z-3-07-sc.meta.html U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) 2008 Updated daily http://walrus.wr.usgs.gov/infobank/s/s708sc/html/s-7-08-sc.meta.html Data have not been independently verified. Undetermined Reference the full report for a description of data coverage. All seismic-reflection data collected on the referenced cruises have been included in this report. Some seismic profiles have gaps in them due to system crashes, mammal shutdowns or hardware maintenance. Shot point numbers in the data files correspond to those in the navigation files. The horizontal positional accuracy of the seismic data thus linked to ship's position is estimated to be within 30 meters. Depths shown in the seismic data files are in milliseconds (round trip travel time) and are referenced to sea level. Refer to report sections "Data Acquisition and Processing" for details of geophysical data acquisition and processing sequence used for data in this report. Ray W. Sliter 2008 Created bathymetry overlay using GMT <http://gmt.soest.hawaii.edu/> Peter J. Triezenberg 2008 Created interactive trackline map using Google Maps API <http://code.google.com/apis/maps/> Peter J. Triezenberg 2008 Created downloadable Google Earth "kmz" file <http://code.google.com/apis/kml/> Peter J. Triezenberg 2008 Created seismic profile images using Seismic Unix <http://www.cwp.mines.edu/cwpcodes/> to provide format options for downloading data. Ray W. Sliter 2008 Converted profiles to TIFF and JPEG files using ImageMagick <http://www.imagemagick.org/> Peter J. Triezenberg 2008 U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Ray W. Sliter Geophysicist mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5194 (650) 329-5190 rsliter@usgs.gov Used GEODAS (GEOphysical DAta System) to create a custom bathymetric and topographic grid for the southern California region covered by the cruise maps. The website is: <http://www.ngdc.noaa.gov/mgg/geodas/geodas.html>. The parameters used are as follows: Grid Database: US Coastal Relief Model Grids Grid Area in degrees and minutes: 34:30 N to 33:48 N, 119:00 W to 120:24 W Grid Cell Size: 3 seconds Grid Format: XYZ (lon, lat, depth), no header, space-delimited, omit empty grid cells. Cell Parameters: 4-byte floating point, tenths of meters Land/Sea Coverage: Sea cells only. Peter J. Triezenberg 2008 U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Peter J. Triezenberg Geologist mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5207 (650) 329-5190 ptriezenberg@usgs.gov Horizontal X and Y locations for the seimic profiles location are provided in ASCII position files and are also stored in the SEG-Y data trace headers in the standard header locations. Universal Transverse Mercator 11 0.9996 -119.0 0.0 500000 0 coordinate pair 3 3 seconds World Geodetic System 1984 WGS 84 6378137 298.257 U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Ray W. Sliter Geophysicist mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5194 (650) 329-5190 rsliter@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 2008-1246 Please recognize the U.S. Geological Survey (USGS) as the source of this information. Physical materials are under controlled on-site access. Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user. This information is not intended for navigational purposes. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. SEG-Y, JPEG, TIFF, ASCII 2.5 gigabytes http://pubs.usgs.gov/of/2008/1246/ none 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. 20080724 U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG) Ray W. Sliter Geophysicist mailing and physical address

USGS, MailStop 999, 345 Middlefield Road

Menlo Park CA 94025-3561 USA (650) 329-5194 (650) 329-5190 rsliter@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 universal time none none