This report provides a brief summary of earthquake activity recorded by the U.S. Geological Survey Northern California Seismic Network in Menlo Park and the University of California Berkeley Seismological Laboratory. It is automatically generated each Wednesday shortly after midnight, Universal time (UT). UT (ie., Greenwich Mean Time) is 8 hours ahead of PST or 7 hours ahead of PDT.
Because it is not possible to review all of the earthquakes before this report is generated, it may contain errors. Please report errors or provide suggestions and comments to ncsn@andreas.wr.usgs.gov
Information about seismicity for other regions is available from the U.S. Geological Survey Earthquake Hazards Program Website. In addition, all earthquake data can be retrieved from the Northern California Earthquake Data Center.
Please note that some of the earthquake data in this report have been reviewed by seismic analysts. Consequently, the parameters that describe the hypocenter, magnitude, origin time, and solution statistics may differ slightly from the information provided at the Northern California Maps of Recent Earthquake Activity website. The differences reflect revised arrival times at seismic stations and the analysts' decisions to include or exclude information from seismic stations.
The minimum magnitude ( M) values in the following bullets reflect the smallest earthquake which the network can routinely record within the region. During the previous seven-day period ending at midnight (UT) Wednesday, our seismic networks recorded
The largest event to occur this week in this region was an earthquake of magnitude 2.6, 2 miles NNE of The Geysers, CA at 02:15 PM UTC Wednesday, 07 30, 2008 (07:15 AM PDT Wednesday, Jul 30, 2008).
The largest event to occur this week in this region was a microearthquake of magnitude 1.9, 9 miles SW of Portola Valley, CA at 11:48 AM UTC Wednesday, 07 30, 2008 (04:48 AM PDT Wednesday, Jul 30, 2008).
The largest event to occur this week in this region was a microearthquake of magnitude 1.4, 11 miles SW of Toms Place, CA at 08:37 AM UTC Wednesday, 07 30, 2008 (01:37 AM PDT Wednesday, Jul 30, 2008).
The following table provides a listing of all M >2 earthquakes that occurred this week. An explanation of the entries in the table is available.
---ORIGIN TIME (UT)--- -LAT N-- --LON W-- DEPTH N RMS ERH ERZ LOC PREF AZ MIN S. PAGE 1 YEAR MON DA HRMN SEC DEG MIN DEG MIN KM RD SEC KM KM REMKS MAG GAP DS PF 2008 JUL 30 1415 0.68 38 49.12 122 47.56 4.31 43 .06 .1 .2 2.6D 73 1 2008 JUL 30 2258 23.42 38 48.36 122 47.79 2.20 33 .06 .2 .3 2.0D 72 0 2008 JUL 31 0326 3.56 41 25.89 122 12.66 0.04 11 .17 .3 2.1 2.2D 51 7
