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 light earthquake of magnitude 4.2, 4 miles NE of Alameda, CA at 11:42 AM UTC Friday, 07 20, 2007 (04:42 AM PDT Friday, Jul 20, 2007).
The largest event to occur this week in this region was a light earthquake of magnitude 4.2, 4 miles NE of Alameda, CA at 11:42 AM UTC Friday, 07 20, 2007 (04:42 AM PDT Friday, Jul 20, 2007).
The largest event to occur this week in this region was a microearthquake of magnitude 2.4, 8 miles W of Toms Place, CA at 05:14 AM UTC Wednesday, 07 25, 2007 (10:14 PM PDT Tuesday, Jul 24, 2007).
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 2007 JUL 19 0902 6.22 38 48.60 122 46.72 4.66 40 .32 .4 .8 2.0D 35 1 2007 JUL 20 0029 11.37 36 27.00 121 0.12 8.71 68 .11 .2 .5 2.2D 64 3 2007 JUL 20 1142 22.36 37 48.24 122 11.58 5.33146 .16 .1 .3 4.2W 16 3 2007 JUL 20 1750 20.35 38 48.40 122 48.40 1.31 42 .05 .1 .3 3.8W 30 1 2007 JUL 20 1751 59.92 38 49.26 122 48.38 1.81 27 .05 .2 .3 2.7D 36 2 2007 JUL 20 1751 59.93 38 49.29 122 48.29 1.83 19 .03 .2 .3 2.7D 49 2 2007 JUL 20 1925 25.47 38 48.79 122 49.06 2.94 39 .09 .2 .6 2.1D 34 2 2007 JUL 21 0048 55.32 37 48.58 122 11.98 5.80103 .17 .1 .3 2.7D 28 4 2007 JUL 21 1840 9.06 39 28.21 122 0.59 23.70 20 .17 .5 1.3 2.1D 89 26 2007 JUL 21 1929 28.47 35 39.19 121 2.92 7.18 40 .09 .2 .5 2.1D 72 7 2007 JUL 22 0027 57.39 35 47.49 121 25.09 5.05 38 .06 .2 .4 2.5D 188 10 2007 JUL 22 0129 57.03 35 46.91 121 27.43 5.42 39 .07 .6 .4 2.2D 216 14 2007 JUL 22 0314 2.07 39 25.36 123 5.95 5.33 22 .05 .2 .9 2.1D 47 17 2007 JUL 22 0523 28.26 39 25.41 123 6.09 5.49 37 .08 .1 1.0 2.1D 38 17 2007 JUL 22 0648 56.85 36 36.13 121 12.83 8.70 60 .06 .1 .2 2.0D 28 4 2007 JUL 22 0948 12.07 39 25.44 123 5.91 6.56 32 .06 .2 .6 2.2D 39 16 2007 JUL 22 2344 4.37 36 51.96 121 31.50 7.92 52 .12 .2 .4 2.0D 35 6 2007 JUL 23 0021 49.55 36 36.27 121 12.57 2.18 46 .07 .1 .5 2.1D 30 4 2007 JUL 23 0526 56.07 36 36.37 121 12.45 2.88 66 .07 .1 .3 2.6D 29 4 2007 JUL 23 0621 44.39 37 30.04 118 50.21 3.40 31 .04 .2 1.0 2.0D 108 7 2007 JUL 23 2145 18.15 40 44.72 122 18.62 1.33 11 .04 .3 7.9 2.1D 98 20 2007 JUL 23 2320 55.44 39 25.46 123 5.83 5.81 16 .08 .3 2.0 2.0D 48 16 2007 JUL 24 1843 1.36 37 19.40 122 6.23 0.12 16 .10 .2 .5 2.2D 73 2 2007 JUL 25 0514 53.50 37 34.50 118 49.70 9.19 40 .06 .2 .5 2.4D 84 2 2007 JUL 25 1823 31.22 40 26.49 124 15.89 24.60 18 .09 .5 .7 3.4L 72 7 2007 JUL 25 2024 30.92 39 59.54 124 3.44 0.04 18 .46 1.6 9.1 2.3D 178 24
