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 a minor earthquake of magnitude 3.2, 4 miles NW of Greenville, CA at 04:05 AM UTC Tuesday, 01 29, 2008 (08:05 PM PST Monday, Jan 28, 2008).
The largest event to occur this week in this region was a microearthquake of magnitude 2.2, 1 miles WNW of Concord, CA at 01:45 PM UTC Tuesday, 01 29, 2008 (05:45 AM PST Tuesday, Jan 29, 2008).
The largest event to occur this week in this region was a microearthquake of magnitude 1.8, 10 miles WSW of Toms Place, CA at 05:25 AM UTC Thursday, 01 24, 2008 (09:25 PM PST Wednesday, Jan 23, 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 JAN 24 2103 45.89 38 48.80 122 48.95 2.83 61 .09 .1 .2 3.2L 31 1 2008 JAN 25 0403 6.83 37 39.39 122 31.10 6.53 71 .11 .2 .3 2.0D 108 4 2008 JAN 25 1341 59.67 40 9.11 122 45.18 5.30 29 .46 .7 1.6 2.4D 45 17 2008 JAN 25 1529 8.59 37 24.86 121 45.86 7.37 69 .08 .1 .4 2.2D 41 5 2008 JAN 26 1310 53.26 40 13.15 122 44.33 10.32 28 .50 .9 1.7 2.9D 68 16 2008 JAN 26 2124 22.35 35 30.12 120 46.97 3.84 77 .14 .2 .9 3.0D 42 10 2008 JAN 27 0141 14.61 38 46.50 122 45.01 0.63 20 .05 .2 .4 2.4D 65 3 2008 JAN 27 0341 32.02 37 25.17 121 45.98 4.53 56 .06 .1 .3 2.0D 44 5 2008 JAN 27 1026 0.17 39 21.29 123 16.88 7.33 12 .04 .3 1.6 2.2D 96 17 2008 JAN 28 1624 39.69 36 44.61 121 20.44 8.14 54 .09 .1 .3 2.5D 43 4 2008 JAN 28 2149 55.58 38 48.49 122 48.80 3.70 61 .06 .1 .2 2.2D 28 1 2008 JAN 29 0334 15.28 36 5.14 120 10.91 13.29 59 .12 .2 .4 2.3D 65 7 2008 JAN 29 0405 41.94 40 10.53 121 1.11 8.00 64 .20 .331.6 3.2L 80 18 2008 JAN 29 1231 1.89 40 10.61 121 1.29 0.16 58 .20 .3 1.5 2.8D 76 19 2008 JAN 29 1345 9.29 37 59.21 122 3.15 16.04 57 .10 .2 .3 2.2D 53 8 2008 JAN 29 1919 56.93 40 10.39 122 44.74 9.89 18 .37 .5 .6 2.9D 86 6 2008 JAN 30 0903 58.06 36 48.63 120 50.81 6.70 39 .04 .3 .6 2.2D 133 4 2008 JAN 30 0923 55.00 39 28.17 122 58.27 9.59 10 .03 .5 .5 2.1D 99 5 2008 JAN 30 1702 40.28 38 50.52 122 49.77 2.53 36 .07 .2 .2 2.0D 126 1 2008 JAN 30 2239 43.92 38 47.22 122 46.28 1.87 30 .05 .2 .3 2.6D 40 2