Earthquake Commentary for June, 2000

Map of recent earthquake activity

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


08:09 PDT, Friday, June 30

A M3.7 quake occurred early this morning, at 2:41 am, 3 miles west of Morongo Valley or 4 miles northwest of Palm Springs. It was felt in the Palm Springs and Banning areas.


18:21 PDT, Thursday, June 29

The week's earthquake list totals 329 this week. Click here to see a summary and map .


09:31 PDT, Wednesday, June 28

A pair of M3.0 quakes occurred overnight. The first was at 9:53 pm, 4 miles north of Beaumont, in San Gorgonio Pass. The other was a Hector aftershock, at 3:32 am, located 36 miles south-southwest of Baker. There was also a M2.6 in the northern Imperial Valley, 3 miles east-northeast of Obsidian Butte, at 1:53 am. We have no indication that any of these was noticed by the public.


09:39 PDT, Tuesday, June 27

Another Hector aftershock occurred yesterday afternoon at 4:48 pm. As with the quakes earlier in the day, the epicentral location was 36 mile south-southwest of Baker. Magnitude was M3.1.

Also, at 8:28 am this morning, there was a M2.8 quake in the Coso Range area, 16 miles east of Coso Junction.


10:34 PDT, Monday, June 26

There was some aftershock action at Hector Mines this morning, including a M4.6 quake at 8:43 am. This was, of course, an aftershock of the October 1999 Hector Mines quake, but it did have an aftershock of its own, a M3.7 at 8:50 am. The epicenters were about 36 miles south-southwest of Baker. This is in the northern part of the aftershock zone. We do have reports that the M4.6 was felt in Barstow and Big Bear. We also have a noticable spike in our "web hits", indicating that a quake was fairly widely felt.


18:30 PDT, Thursday, June 22

The week's earthquake list totals 332 this week. Click here to see a summary and map .


16:10 PDT, Friday, June 16

The week's earthquake list totals 432 this week. Click here to see a summary and map .


15:42 PDT, Wednesday, June 14

The Imperial Valley swarm continues. At 2:49 pm, the region was shaken by a M4.5 quake 6 miles south-southeast of Brawley. It was felt as far away as Palm Springs. These two M4+ quakes have been accompanied by about 50 to 60 smaller events, eight of which were in the M3 range.

The epicentral area is in the southern Brawley Seismic Zone. This zone connects the San Andreas fault (at its northern end) with the Imperial fault (at its southern end). In the past few decades, the Brawley Seismic Zone has been a prolific source of earthquake swarms, a few including M5+ quakes. Swarms in 1975 and 1976 occurred close to the current site.


12:35 PDT, Wednesday, June 14

At 12:00 noon today, the Imperial Valley experienced a moderate earthquake. Magnitude was M4.2 and the epicenter was 6 miles south-southeast of Brawley. We do have reports that the quake was felt in the El Centro and Brawley areas. About a dozen aftershocks have been noted so far, three of them having magnitudes of M3.0 (at 12:10, 12:20 and 12:32 pm). Check back a little later for more updates.


21:11 PDT, Sunday, June 11

We've had a slew of earthquakes today and all over M3.0. The largest and most recent was a premilinary M4.0 which occurred this evening at 8:15 pm (PDT) and was located 38 miles north of Joshua Tree. This earthquake is an aftershock to the M7.1 Hector Mine earthquake (Oct. 16th, 1999). It is unknown whether it was felt. Roughly an hour earlier at 7:16 pm there was a preliminary M3.0 earthquake located 4 miles south of Morongo Valley, near the border of San Bernardino and Riverside County. Moving south and earlier in the day there was a preliminary M3.0 earthquake near the Imperial county city of Obsidian Butte at 10:26 am today. It is not known if this earthquake too was felt. An earthquake that missed earlier recognition was a M2.8 that occurred at 11:42 pm Friday, June 8th. It was the, so far, largest earthquake in a recent swarm that developed roughly 6 miles north-northeast of Moorpark.


16:35 PDT, Friday, June 09

The week's earthquake list totals 338 this week. Click here to see a summary and map .


10:17 PDT, Wednesday, June 07

There were two quakes of interest overnight. The first was a M2.9 Landers aftershock at 7:08 pm last night. The epicenter was 15 miles north of Yucca Valley. The second was an Obsidian Butte quake, M3.3 at 9:45 pm. It's epicenter was located 2 miles east-northeast of Obsidian Butte. As far as we know, neither was felt.


11:00 PDT, Monday, June 05

A number of small earthquakes occurred in the region over the weekend. These included a M2.8 at 4:32 am on Saturday, located 4 miles north of Lake Henshaw. At 8:37 pm on Saturday, a M2.7 Landers aftershock occurred 15 miles north of Yucca Valley. At 12:50 am this morning, another M2.8 occurred under the ocean 16 miles south-southwest of Palos Verdes Point. Finally, at 6:37 am this morning (Monday), there was a M2.7 located 4 miles northwest of Morongo Valley. We have not had any reports that any of them were felt; only the Palos Verdes Point quake made the news at all.


08:41 PDT, Friday, June 02

A small swarm of earthquakes has occurred this morning in the northern Imperial Valley. These include a M3.5 at 7:24 am and a M2.7 at 7:29 am. The epicenters are located 2 miles east-northeast of Obsidian Butte. A minor spike in the web site "hit" statistics indicates that at least the large one may have been felt. Those who follow this earthquake commentary will realize that this area is a prolific source of small quakes.

Just before the Obsidian Butte activity started, a M2.9 Hector aftershock occurred. This one was at 7:01 am, 35 miles north of Joshua Tree.


17:31 PDT, Thursday, June 01

The week's earthquake list totals 323 this week. Click here to see a summary and map .


This page is www.trinet.org/eqreports/comments/June2000.html.
Last updated 08:09 PDT June 30, 2000.