Magnitude 3.9 NORTHERN CALIFORNIA
Friday, July 20, 2007 at 17:50:20 UTC
Seismic Hazard Map
Major Tectonic Boundaries: Subduction Zones -purple, Ridges -red and Transform Faults -green
Preliminary Earthquake Report
U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver