Earthquake Commentary for November, 1998

Map of recent earthquake activity

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09:32 PST, Monday, November 30

The Thanksgiving weekend was relatively quiet, seismically speaking. At 9:20 pm on Saturday, there was a M2.6 Landers aftershock, located 2 miles north of Yucca Valley, with no 'felt' reports.

14:27 PST, Friday, November 27

We recorded and analysed 184 earthquakes in the past week. Click here to see a summary and map .

16:46 PST, Wednesday, November 25

On Monday night, at 8:36 pm, there was a M2.8 located 7 miles east-southeast of Hemet, in the San Jacinto fault zone.

Following that, very early (1:15 am) on Tuesday morning, a M2.5 quake occurred in the Lytle Creek area, 1 mile south of Devore, also near the San Jacinto fault. A M3.3 occurred near there last Friday, but at a slightly different location.

At 6:02 pm on Wednesday, there was a M2.9 located 12 miles east of Coso Junction. This is a common source of microearthquakes in the Coso Range.

Then at 1:20 am, a M2.7 occurred near the San Andreas fault, 3 miles northwest of Frazier Park.

Finally, at 8:17 am this morning, there was a M2.7 located 4 miles southwest of Banning.

We have received no inquiries on any of these minor quakes.

09:12 PST, Monday, November 23

The only quake of possible interest this weekend was a M2.9 in the Coso Range area, 5 miles south-southeast of Coso Junction. It occurred at 7:30 pm last night. Since the Coso Range is a remote area, we do not expect to get public inquiries about this quake.

16:34 PST, Friday, November 20

We have just had a M3.3 located 3 miles west of Devore. The time was 3:58 pm, and the epicenter was located near Lytle Creek, southwest of Cajon Pass. It was close to the San Jacinto fault. Today's event had a mostly strike-slip focal mechanism that agrees well with the strike of the San Jacinto. We have not received any inquiries yet.

16:27 PST, Thursday, November 19

We recorded and analysed 167 earthquakes in the past week. Click here to see a summary and map .

14:10 PST, Wednesday, November 18

At 12:13 pm today, there was a M2.7 Northridge aftershock, located 4 miles northwest of San Fernando. It was felt.

09:20 PST, Wednesday, November 18

We had a small Whiskey Springs aftershock this morning, at 7:49 am. It was located 4 miles north of Big Bear City, and had a magnitude of M2.9. The last one of these that exceeded M2.5 was a M3.1 on November 4. The Whiskey Springs earthquake, if you recall, was a M4.9 that occurred on October 26. We have no indication that this morning's quake was felt.

11:09 PST, Sunday, November 15

There have been three quakes of minor interest so far this weekend. The first occurred at 7:26 pm on Friday, 15 miles north-northwest of Borrego Springs, in the complex San Jacinto fault zone. The magnitude was M2.6.

The second was also a M2.6, this time at 3:19 pm Saturday, located 8 miles east-northeast of Ojai.

The third one occurred early this morning, at 3:14 am, 6 miles north-northeast of Ocotillo Wells. Its magnitude was M3.3. This epicenter is also not far from the San Jacinto fault zone. We have received no public inquiries about any of these quakes.

16:44 PST, Thursday, November 12

We recorded and analysed 161 earthquakes in the past week. Click here to see a summary and map .

07:45 PST, Wednesday, November 11

There was a little excitement yesterday evening at about 9:40 pm: a M2.5 under Encino. The depth was 11.3 km (about 7 miles), which puts the hypocenter well above and slightly to the southeast of the Northridge rupture zone. In other words, yesterday's quake was not an aftershock. It was 'felt far and wide', according to our Media Relations office.

13:48 PST, Tuesday, November 10

At 12:59 pm today, there was a M3.5 Landers aftershock, located 2 miles north of the town of Yucca Valley. Since Yucca Valley residents routinely feel quakes below M2.5, we should assume that today's quake was felt.

09:14 PST, Tuesday, November 10

The only earthquake of any interest recently was a M3.6 located offshore, 38 miles south of San Clement Island, or 77 miles west-southwest of San Diego. It happened at 6:13 am today. There have been no 'felt' reports.

16:47 PST, Thursday, November 05

We recorded and analysed 226 earthquakes in the past week. Click here to see a summary and map .

08:40 PST, Thursday, November 05

At 8:11 pm last night, there was a M2.9 quake in the San Gorgonio Pass area, 1 mile east-northeast of Beaumont. I have no word on whether or not it was felt.

17:19 PST, Wednesday, November 04

There was also a small Landers aftershock today: a M2.5 at 1:49 pm this afternoon, located 2 miles north-northwest of Yucca Valley.

09:35 PST, Wednesday, November 04

A Whiskey Springs aftershock (of the October 26 M4.9), this one M3.1, was felt at 11:21 pm last night. Like the others, it was located 4 miles north of Big Bear City, near the northern front of the San Bernardino Mtns.

12:05 PST, Tuesday, November 03

There were two small quakes of interest this morning. The first, at 3:51 am, occurred 1 mile east of Obsidian Butte, nearly the same location as the M3.9 yesterday, and had a magnitude of M2.6. The second was a Whiskey Springs aftershock, M2.5, at 10:48 am. Neither was apparently felt.

13:35 PST, Monday, November 02

There were a couple of quakes early this morning that were close to (or equal to) M4. The first was a M4.0 that occurred 56 miles south-southwest of Calexico, in northern Baja. Note that its epicenter is about 40 km to the southwest of the Baja swarm of two weeks ago.

The second moderate event, which reached M3.9, occurred this morning at 7:53 am, 2 miles northeast of Obsidian Butte, in the Brawley Seismic Zone. There was a M2.5 foreshock about a minute and a half earlier. It seems unlikely that the Baja event would have been felt in the U.S., but the Obsidian Butte quake ought to have been fairly widely felt in the Imperial Valley.

There were a handfull more Whiskey Springs aftershocks over the weekend, as well: in particular, a M2.7 at 6:50 am on Saturday, a M3.0 at 1:28 am on Sunday, and a M2.6 at 5:03 am today. None were reported to us as 'felt'.

There was also a M2.5 Landers aftershock at 4:55 am on Saturday, located 4 miles north of Yucca Valley, and a M2.8 at 7:15 am on Sunday, 16 miles south of Calexico.

Last updated 09:32 PST November 30, 1998
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