California State Waters Map Series—Offshore of Monterey, California

This part of DS 781 presents bathymetric contours for several seafloor maps of the Monterey Canyon and Vicinity map area, California. The raster data file is included in "Contours_MontereyCanyon.zip," which is accessible from http://dx.doi.org/10.3133/ofr20161110. Bathymetric contours of the Monterey Canyon and Vicinity map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS), by Monterey Bay Aquarium Research Institute (MBARI), and by California State University, Monterey Bay (CSUMB). Mapping was completed between 1998 and 2014 using a combination of 30-kHz Simrad EM-300 and 200-kHz/400-kHz Reson 7125 multibeam echosounders, as well as 234-kHz and 468-kHz SEA SWATHplus bathymetric sidescan-sonar systems. The mapping missions collected bathymetry data from about the 10-m isobath to beyond the 3-nautical-mile limit of California's State Waters. Bathymetric contours were generated separately from the modified 2-m and 5-m bathymetric surface then merged to one final contour dataset.10-m intervals were generated in water depths shallower than 100 m, at 50-m intervals from 100 to 200 m, and at 200-m intervals in water depths deeper than 200 m. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 m (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved; smaller segments and isolated island polygons were excluded from the final output.