The Los Angeles, California Margin was mapped using multibeam echosounders during three separate surveys (Figure 1). In 1996, the USGS surveyed the shelf and slope in Santa Monica Bay from Pt. Dume to south of the Palos Verdes Peninsula. The mapping was accomplished using a Kongsberg Simrad EM1000 multibeam sonar system that provided high-quality bathymetry and quantitative backscatter. In 1998, the USGS continued the mapping to the south and surveyed the outer shelf, slope, and proximal basin off Long Beach and Newport using a Kongsberg Simrad EM300 multibeam sonar system. In 1999, the Los Angeles Margin mapping was completed with the surveying of the inner Long Beach shelf from the Palos Verdes Peninsula, south to Newport. This survey used a dual Kongsberg Simrad EM3000D multibeam sonar system.
These three surveys were conducted to support USGS projects studying marine pollution and geohazards along the Los Angeles Margin.
