Chase and others (1981) used the following sources to compile the published and unpublished maps. Data for the area seaward of the continental slope (water depths greater than approximately 2000 meters) were obtained primarily from the U.S. Coast and Geodetic Survey's (C&GS) 1955 Pacific Exploratory Survey, a systematic and detailed (approximately 8-nautical mile trackline spacing) survey between Mexico and Canada. The U.S. Geological Survey provided data from cruises S3-78-NC, S15-78-NC, L2-77-NC, L10-76-NC, K-73-NC, and Bartlett 72. Data were also obtained from Scripps Institution of Oceanography (SIO) cruises Merazine, Blue Flash, Kayak B, Scan I, and Seven Tow (Chase and Menard, 1971; Chase and others, 1975; Wilde and others, 1976). The 200-meter contour was derived from the National Ocean Service (NOS) and Coast and Geodetic Survey (C&GS) charts 1206N-15, 1206N-16, 1306N-19, 1306N-20, 1307N-11B, 1307N-18, and 1308N-12.
Between 40 degrees N and 49 degrees N latitude the bathymetric contours were obtained from five sources. Boundaries of the areas covered by each data source are provided in the graphics display. In the area bounded by 44 degrees N and 45.5 degrees N latitude, and 125 degrees W and 126 degrees W longitude, contours were computer drawn from gridded digital data gathered by the NOAA. The original data are from high-resolution bathymetric surveys conducted in the U.S. Pacific EEZ by the NOS using multi-beam, swath-sounding techniques.
For the remainder of the continental slope, the Cascadia Basin, the Gorda Basin, and the Tufts Abyssal Plain the contours were scanned from the maps and work sheets of Chase and others (1981). Just as in the 30 degrees N - 40 degrees N area, data used in the region seaward of the continental slope were obtained primarily from the C&GS 1955 Pacific Exploratory Survey. Also data were used from USGS cruises S3-78-NC, S15-78-NC, L2-77-NC, L10-76-NC, K-73-NC, and Bartlett 72 and from SIO cruises Kayak B, Scan I, and Seven Tow (Chase and Menard, 1971; Wilde and others, 1979; Wilde and others, 1978; Wilde and others, 1977).
The 200-meter contour was derived from the C&GS charts 1308N-12, 1308N-17, and 1308N-22.
These data are not to be used for navigation purposes. Mariners should refer to the appropriate nautical chart.
The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.