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 4.4, 4 miles W of Glen Ellen, CA at 03:08 AM UTC Thursday, 08 03, 2006 (08:08 PM PDT Wednesday, Aug 02, 2006).
The earthquake near Glen Ellen (southeast of Santa Rosa) on Thursday, Aug 03 (GMT), 2006 (08:08 PM PDT Wednesday, Aug 02, 2006) was widely felt in the north bay, east bay, San Francisco, and the S.F. peninsula. Shaking intensity felt in the epicentral area reached intensity classed as "strong" (intensity VI, "felt by all", capable of knocking small items from shelves, cracking weak plaster and moving furniture). The earthquake was at a typical 8.8 km (5 miles) depth. It was on or close to the Rodgers Creek fault. The Rodgers Creek is the northern extension (north of San Pablo Bay) of the Hayward Fault. According to the earthquake probability working group of the USGS, either the Rodgers Creek or Hayward Faults (or both faults combined) have a 27% chance of producing a magnitude 6.7 or larger earthquake in the next 30 years. This is the highest probability of any fault system in the San Francisco bay area. Earthquakes on the Rodgers Creek Fault are closely monitored.
The largest event to occur this week in this region was a light earthquake of magnitude 4.4, 4 miles W of Glen Ellen, CA at 03:08 AM UTC Thursday, 08 03, 2006 (08:08 PM PDT Wednesday, Aug 02, 2006).
The largest event to occur this week in this region was a microearthquake of magnitude 2.5, 10 miles WSW of Toms Place, CA at 03:16 PM UTC Tuesday, 08 08, 2006 (08:16 AM PDT Tuesday, Aug 08, 2006).
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 2006 AUG 3 0308 12.86 38 21.81 122 35.32 8.86 92 .14 .1 .3 ROG 4.4W 28 2 AW 2006 AUG 3 0409 52.07 38 22.44 122 35.06 7.43 45 .08 .2 .2 ROG 2.1D 35 3 AA 2006 AUG 3 0522 14.77 36 39.53 121 16.94 7.42 62 .06 .1 .3 STN 2.9D 45 1 NN 2006 AUG 3 0901 12.17 38 48.02 122 47.93 3.43 48 .07 .2 .3 GEY 2.2D 27 1 AA 2006 AUG 3 1110 11.93 38 48.12 122 46.86 3.64 40 .07 .2 .4 GEY 2.1D 39 1 AA 2006 AUG 3 1348 49.57 36 42.96 121 11.03 1.04 34 .18 .4 3.6 PAI 2.1D 51 6 NN 2006 AUG 4 0213 16.31 35 42.46 121 8.17 6.70 35 .07 .3 .5 SSM 2.3D 106 3 XX 2006 AUG 4 0818 53.61 39 27.03 123 7.05 6.85 25 .09 .2 1.6 BAR 2.1D 47 17 AA 2006 AUG 5 0303 53.24 40 32.53 123 13.06 29.61 13 .08 .4 1.0 KLA 2.6D 50 13 XX 2006 AUG 5 0357 40.54 40 32.55 123 13.20 29.45 11 .08 .4 1.1 KLA 2.3D 90 13 XX 2006 AUG 5 0745 15.41 38 48.42 122 44.35 2.39 43 .08 .2 .3 GEY 2.2D 60 1 AA 2006 AUG 5 0803 40.65 36 47.46 121 31.72 10.63 75 .12 .2 .3 SJB 2.7D 43 4 NN 2006 AUG 5 1303 46.65 36 22.28 120 36.21 9.72 59 .15 .2 .6 CRV 2.3D 98 16 NN 2006 AUG 6 0600 52.05 38 6.63 121 52.70 20.38 47 .18 .4 .2 JQN 2.2D 95 8 AW 2006 AUG 6 1056 39.25 37 31.87 118 26.16 9.98 35 .06 .3 1.0 CHV 2.5D 121 11 QQ 2006 AUG 6 2003 48.81 38 41.93 122 52.29 7.14 34 .08 .2 .6 ROG 2.3D 36 8 AA 2006 AUG 7 0908 45.44 36 12.26 120 19.76 10.61 45 .08 .2 .2 COA 2.9D 55 5 KN 2006 AUG 7 1004 54.88 36 12.34 120 19.88 10.19 37 .10 .3 .3 COA 2.0D 147 5 KA 2006 AUG 7 1424 46.15 36 35.16 121 11.32 6.82 34 .06 .2 .4 PIN 2.0D 34 1 NN 2006 AUG 7 1639 56.09 37 53.33 122 14.22 6.67 57 .07 .1 .2 HAY 2.1D 50 1 AW 2006 AUG 7 1820 4.52 40 28.55 124 17.87 19.65 8 .13 2.5 1.3 EUR 2.5D 153 3 WW 2006 AUG 8 1516 48.07 37 28.85 118 50.30 5.71 44 .06 .2 .7 MOR 2.5D 117 8 II 2006 AUG 8 1742 18.51 40 27.16 123 52.03 20.06 17 .14 .4 1.1 EUR 2.5D 68 31 WW 2006 AUG 8 1946 26.97 38 25.28 122 14.57 7.66 60 .23 .2 .5 GVL 2.9D 71 2 AA
