100m Depth Contours

Abstract: Bathymetry for the California, Oregon, Washington Exclusive Economic Zone (EEZ). Bathymetry contours range from 100-m contours from 200m to maximum depth.

Purpose: These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display information about the deep water Pacific Ocean area of the U.S. westcoast.

Supplemental_Information: Most of the contours between 30 degrees N and 40 degrees N were scanned from a 1:1,000,000 scale map published by Chase and others (1981) and from 1:250,000 scale unpublished work sheets made in conjunction with the map compilation. Contours from areas not included in the 1981 map were scanned from unpublished maps.

Chase and others (1981) used the following sources to compile the published and unpublished maps.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.