Strong-motion data

The April 25, 1992, mainshock (M=7.) near Petrolia and the two largest afterschokcs (M=6.6 and M=6.7) were recorded by networks of strong-motion accelerographs operated by the U.S Geological Survey (USGS) and the State of California Strong-Motion Instrumentation Program (CSMIP). The map on the next page shows the locations of USGS and CSMIP strong-motion stations in the Cape Mendocino region