The map of global seismicity is based on earthquakes contributed to the CNSS Global earthquake catalog . Earthquakes with magnitude 5.5 and larger are plotted in a Mercator projection. The map of northern California seismicity is based on earthquakes reported by the Berkeley Seismological Laboratory and the USGS Menlo Park in the Northern California earthquake catalog . Earthquakes with magnitude 3.0 and larger are plotted with red circles in a Mercator projection.
Grey lines indicate major faults.
The detail maps of northern California are also based on the earthquake catalogs of the Berkeley Seismological Laboratory and the USGS Menlo Park. Earthquakes with magnitude 2.0 and larger are plotted with red circles. The earthquake lists contain information on the origin time, location, depth, and magnitude of these events. In addition, a number of parameters are provided which measure how well the earthquake is located. For an explanation of the output format, please read the manual page .