Earthquake Commentary for December, 2001

Map of recent earthquake activity

Did you feel it?

Send comments and suggestions to:kate@gps.caltech.edu


16:09 PST, Thursday, December 27

We have recorded and located 169 earthquakes in the last week. Click here to see a summary and map .


16:06 PST, Thursday, December 20

We have recorded and located 192 earthquakes in the last week. Click here to see a summary and map .


15:29 PST, Wednesday, December 19

At 2:57 pm this afternoon, there was a M2.9 quake felt in the Rancho Cucamonga and Etiwanda areas. The epicenter was 5 miles north-northwest of Rancho Cucamonga (slightly north of the mountain front), and the depth was about 8 miles.


06:21 PST, Friday, December 14

Many people in the Inland Empire and Orange County were awakened early this morning by a magnitude M3.9 earthquake. The time was 4:01 am, and the quake was located 5 miles southeast of Chino. The focal mechanism shows strike-slip motion, or horizontal motion on a vertical fault. There have been half a dozen aftershocks so far, ranging from M1.4 to M2.2, and one foreshock (at the same epicenter). The foreshock was a M1.9 at 3:00 am. Interestingly, there was also a M1.7 at 3:12 am, located 6 miles east-southeast of Yorba Linda. The M3.9 mainshock appears to have been felt as far away as Temecula and Palmdale, with the highest intensity at Modified Mercalli IV in the epicentral area.


16:19 PST, Thursday, December 13

We have recorded and located 231 earthquakes in the last week. Click here to see a summary and map .


09:34 PST, Thursday, December 13

There was a small quake in the Coso/Rose Valley area this morning, at 9:16 am. Magnitude was M2.9, and the epicenter was located 4 miles southeast of Coso Junction. This quake was probably felt in the China Lake area, but so far we have no reports.


13:58 PST, Tuesday, December 11

The San Bernardino Mountains experienced a M3.6 quake early this afternoon, at 1:40 pm. The epicenter was located 6 miles east of Mt. San Gorgonio, and focal mechanism appears to be mostly strike-slip. We have reports so far that this quake was felt in the Big Bear area.


07:54 PST, Monday, December 10

A M5.2 quake occurred Saturday afternoon, at 3:36 pm, in Baja near the delta of the Colorado River, near the northern end of the Gulf of California. This quake was felt in the U.S., in the San Diego area, as far north as Temecula, as well as in the Imperial Valley, Yuma, and Blythe. It was followed at 5:42 pm (same day) by a M4.5 aftershock, which was also felt in San Diego, Imperial Valley, Yuma, and Blythe. Note that these quakes do not appear on the "Recent Earthquakes" maps because their epicenters were too far south.


12:58 PST, Friday, December 07

At 12:47 pm this afternoon, there was a M3.4 Landers aftershock, located 20 miles north of Yucca Valley. It should have been felt in the Landers and Johnson Valley areas, but we have no reports as yet.


16:25 PST, Thursday, December 06

We have recorded and located 202 earthquakes in the last week. Click here to see a summary and map . No-one felt any quakes all week.


This page is www.trinet.org/eqreports/comments/December2001.html.
Last updated 16:09 PST December 27, 2001.