Edward M. Sweeney 2004 Vector U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA U.S. Geological Survey http://pubs.usgs.gov/of/2004/1082/arcgis/shape//tracklines/Tracklines.zip Edward M. Sweeney William W. Danforth Herman A. Karl Thomas F. O'Brien William C. Schwab 2004 USGS Open-File Report 2004-1082 USGS, Woods Hole Science Center, Woods Hole, MA USGS http://pubs.usgs.gov/of/2004/1082 In 1989, the U.S. Geological Survey (USGS) began a major geologic and oceanographic investigation of the Gulf of the Farallones continental shelf system, designed to evaluate and monitor human impacts on the marine environment (Karl and others, 2002). The study region is located off the central California coast, adjacent to San Francisco Bay and encompasses the Gulf of the Farallones National Marine Sanctuary. Geologic mapping of this area included the use of various remote sensing and sampling techniques such as sub-bottom profiling, sidescan-sonar and bathymetric mapping, gravity core and grab sampling, and photography. These data were used to define the surficial sediment distribution, underlying structure and sea floor morphology of the study area. The primary focus of this report is to present a georeferenced, digital sidescan-sonar mosaic of the study region. The sidescan-sonar data were acquired with the AMS-120 (120kHz) sidescan-sonar system during USGS cruise F9-89-NC. The dataset covers approximately 1000 kmē of the continental shelf between Point Reyes, California and Half Moon Bay, California, extending west to the continental shelf break near the Farallon Islands. The sidescan-sonar mosaic displays a heterogenous sea-floor environment, containing outcropping rock, ripples, dunes, lineations and depressions, as well as flat, featureless sea floor (Karl and others, 2002). These data, along with sub-bottom interpretation and ground truth data define the geologic framework of the region. The sidescan-sonar mosaic can be used with supplemental remote sensing and sampling data as a base for future research, helping to define the local current regime and predominant sediment transport directions and forcing conditions within the Gulf of Farallones. These data represent the sidescan-sonar trackline navigation data during the geophysical survey in the Gulf of the Farallones off the coast of central California. 19890802 19890815 ground condition Complete None planned -123.383570 -122.688740 37.977070 37.587810 General Sidescan-Sonar AMS-120 USGS U.S. Geological Survey Woods Hole Science Center Coastal and Marine Geology Program CMGP trackline navigation AMS-120 seafloor mapping field activity identifier F9-89-NC field activity serial number 89020 General Farallones Gulf of the Farallones California U.S. West Coast U.S. Pacific Coast North America Pacific Ocean United States Half Moon Bay Point Reyes Farallon Islands Bodega Bay San Francisco None Public domain data from the U.S. government is freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of this dataset. Edward M. Sweeney U.S. Geological Survey Research Assistant mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 (508) 548-8700 x2307 (508) 457-2310 esweeney@usgs.gov Microsoft Windows 2000 Version 5.1 (Build 2600) Service Pack 1; ESRI ArcCatalog 8.3.0.800 These data represent the sidescan-sonar tracklines conducted during a geophysical cruise within the Gulf of Farallones in 1989 by the U.S. Geological Survey. These data were navigated by GPS and LORAN-C. For real time positioning, the primary system was chosen either manually by the navigator or selected automatically by computer. Tracklines were within 100m of preplotted tracks when using GPD and LORAN-C and within a few meters when navigating under the Del Norte system. These data represent the sidescan-sonar tracklines conducted during a geophysical cruise within the Gulf of Farallones in 1989 by the U.S. Geological Survey. Navigation data was acquired using three systems: (1) Global Positioning System (GPS); (2) LORAN-C; and (3) shore-based, line-of-sight transponder net (Del Norte system). For real time positioning, the primary system was chosen either manually by the navigator or selected automatically by computer. The navigation is reformatted into a comma-delimited ArcView Ungenerate text format. The file is then imported into ArcView, and a vector line shapefile is generated. The line numbers for each trackline are stored in an ASCII file listing unique track ID and line number. This file is imported into ArcView and ArcMap as a table. The file is then joined to the line shapefile by the unique track ID. The table for the trackline file is then edited, a new field created and the line number information is written to this new field. After writing the line number information to the trackline shapefile, the table join is removed, and the file is saved. This permanently saves the line number with the corresponding trackline. 2004 Edward M. Sweeney U.S. Geological Survey Research Assistant Physical

384 Woods Hole Road

Woods Hole MA 02543 USA 508-548-8700 x2307 508-457-2310 esweeney@usgs.gov Vector String 358 0.000089992 0.000089992 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.257224 Tracklines ESRI ArcGIS 8.3 vector shapefile ESRI FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. LineNumber Internal Definition ESRI Internal identification value Nancy Soderberg U.S. Geological Survey Data Librarian mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 USA (508) 548-8700 x2275 (580)457-2313 nsoderberg@usgs.gov Sidescan-sonar Tracklines (ESRI Shapefile) Although this data set and its lineage have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data or its related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related items. Users must assume responsibility for the proper use of these data. The data should not be used at resolutions for which they are not intended. The data have not been reviewed for conformity with U.S. Geological Survey editorial standards, or the North American Strigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government. 20040407 Edward M. Sweeney U.S. Geological Survey Research Assistant mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543 (508) 548-8700 x2307 (508) 457-2310 esweeney@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time http://www.esri.com/metadata/esriprof80.html ESRI Metadata Profile