Earthquake Commentary for August, 2001

Map of recent earthquake activity

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18:02 PDT, Thursday, August 30

We have recorded and located 306 earthquakes in the last week. Click here to see a summary and map .

15:24 PDT, Tuesday, August 28

A quake was fairly widely felt from Palm Springs to Escondido early this afternoon. The time was 2:30 pm, and the magnitude was M3.4. Some of the places where people reported feeling the quake were: Palm Springs, Cathedral City, Banning, Idyllwild, Hemet, Pine Cove, Temecula, and Escondido.

16:53 PDT, Sunday, August 26

Three small, but possibly felt, quakes have occurred so far this weekend. The first was at 9:43 pm last night, 5 miles west of Grapevine (at the bottom of the Grapevine Grade on the I5). The magnitude was M2.8.

Another M2.8 occurred later last night, at 10:39 pm. That quake was located in Mexico, 29 miles southeast of Calexico.

A M2.7 occurred this afternoon at 4:25 pm. This quake was located in the Sierras, 25 miles east-southeast of Porterville. It was felt in Springville.

17:57 PDT, Thursday, August 23

We have recorded and located 340 earthquakes in the last week. Click here to see a summary and map .

13:01 PDT, Thursday, August 23

A very small quake (M2.3) was felt late this morning in Acton. The epicenter was 3 miles west-southwest of Palmdale, and the time of the quake was 11:23 am.

08:05 PDT, Thursday, August 23

It seems that the July Coso swarm is not entirely over. At 4:25 am this morning, there was a M3.1, located 3 miles east of Coso Junction. We have no 'felt' reports so far.

08:26 PDT, Wednesday, August 22

At 12:50 am this morning, there was a M2.9 quake 9 miles south-southwest of Calexico (in Mexico). Also, at 6:06 am, there was a M3.1 Hector Mines aftershock, located 32 miles north of Joshua Tree. Neither was, as far as we know, felt.

08:13 PDT, Monday, August 20

At 12:34 am today, a small quake was felt in the Inland Empire. The epicenter was 1 mile southeast of Loma Linda, and the magnitude was 3.1. We have "felt" reports from Riverside, Moreno Valley, and Rancho Cucamonga.

There were also two quakes of interest yesterday. A M2.8 occurred at 6:12 am, 5 miles southeast of Coso Junction. Then, at 6:26 pm, there was a M3.2 Hector Mines aftershock, located 34 miles north of Joshua Tree.

10:28 PDT, Friday, August 17

At 3:06pm yesterday we had a M4.2 aftershock to the M4.4 earthquake that occurred earlier near San Clemente Island. It's been reported that the aftershock was felt weakly along the neighboring islands and the shoreside communities of Los Angeles, Orange and San Diego counties. Like its precursor it too shows strike-slip, horizontal movement. In December of 1951 there was a M5.9 in the general region to yesterday's earthquakes so it's not surprising to have earthquakes offshore. Probably quite of few people of Orange and San Diego county remember the M5.4 Oceanside earthquake in July of 1986 which occurred 32 miles offshore from the city of Oceanside.

17:29 PDT, Thursday, August 16

We have recorded and located 433 earthquakes in the last week. Click here to see a summary and map .

14:15 PDT, Thursday, August 16

There have been two significant aftershocks to this morning's San Clemente Island quake: a M3.2 at 1:04 pm and a M3.1 at 1:37 pm. Both occurred in the same area, south-southeast of San Clemente Island.

11:30 PDT, Thursday, August 16

Add Santa Monica, Anaheim, Newport Beach, Lake Forest, Buena Park, Fountain Valley, La Palma, San Juan Capistrano, San Clemente, Carlsbad, La Jolla, and San Diego to the "felt" list.

The focal mechanism shows strike-slip (horizontal motion of the fault) with a stike consistent with many of our offshore faults, including the nearby San Clemente fault.

11:18 PDT, Thursday, August 16

A M4.4 quake has just happened offshore, 7 miles south-southeast of San Clemente Island, or 65 miles due west of San Diego. We are currently getting "felt" reports from Irvine, Santa Ana, Brea, Huntington Beach, Mission Viejo, Costa Mesa, Tustin, Orange, Laguna Niguel, Alisa Viejo, and Solano Beach. The time was 11:04 am.

13:35 PDT, Monday, August 13

There were a couple of quakes of interest in northern California over the weekend, notably a M5.4 at 1:19 pm on Friday, 9 miles west of Portola. This quake was widely felt as far as Sacramento and Reno.

At 7:06 am this morning, a M3.8 occurred near the coast 16 miles north-northwest of San Simeon. It was felt in the epicentral area.

11:30 PDT, Friday, August 10

We have recorded and located 607 earthquakes in the last week. Click here to see a summary and map .

10:41 PDT, Tuesday, August 07

At 9:52 am this morning, a M3.5 quake occurred in northern Baja, 47 miles southeast of San Ysidro. The quake was felt in the U.S. at San Diego, Ramona, and Alpine.

08:38 PDT, Monday, August 06

At 12:05 pm on Saturday, there was a M3.2 earthquake at a different location: 6 miles north of the town of Lake Isabella. It was felt in Lake Isabella, Kernville, Woffard Heights, and Fresno.

13:04 PDT, Friday, August 03

At 10:35 am today, a M2.9 quake occurred 4 miles southeast of Ridgecrest. Due to its size, it was probably felt in Ridgecrest, but we have no reports so far. Note that this quake is not part of the ongoing swarm; its epicenter was about 37 miles south-southeast of Coso Junction.

17:49 PDT, Thursday, August 02

We have recorded and located 774 earthquakes in the last week. Click here to see a summary and map .

10:06 PDT, Thursday, August 02

At 9:21 am this morning, there was a M3.9 (according to University of Nevada at Reno) quake in the Eureka Valley/Saline Valley area, 25 miles east of Big Pine. Big Pine is in the Owens Valley, southeast of Bishop. We have not 'felt' reports so far on the quake.

17:37 PDT, Wednesday, August 01

There has been another Coso swarm member: a M3.0 at 2:31 pm today, located 3 miles east-northeast of Coso Junction.

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Last updated 15:24 PDT August 28, 2001.