There have been no reports of major damage following a 4.0 earthquake that struck near Alamo in unincorporated Contra Costa County at 9 p.m. Friday.
The quake was centered 2 miles east northeast from Alamo and 4 miles north northwest of Danville, according to the U.S. Geological Survey. It had a recorded depth of about 10 miles, the USGS said.
USGS seismologist David Oppenheimer said the quake was along a fault line that does not have a name because it does not rupture the surface.
Oppenheimer said the last time the fault was active was in April 1990 when a sequence of quakes shook the area for three to four weeks.
Oppenheimer said that sequence included 18 quakes of at least 3.0 and caused some structural damage along the fault line.
But he said it's too early to know if this quake will have a similar result. Oppenheimer said the 10-mile depth of the tremor means there was more rock between the quake and the surface, resulting in shaking that was not felt as strongly.
By 10 p.m., there had already been three aftershocks, none of which registered as more than a 1.9.
The USGS reported that the initial tremor was felt as far away as Modesto, Watsonville and Napa.
The quake caused Bay Area Rapid Transit trains to stop systemwide for nine minutes, said spokesman Linton Johnson, who added that stopping trains after an earthquake for about five minutes is protocol.
After stopping the trains, BART officials let the trains run again but at a slower speed so that any damage could be reported back. Johnson said there had been no reports of structural damage to the BART lines.
By 10 p.m., BART was still experiencing delays up to five to 10 minutes.
Officials with the Oakland International Airport, the closest airport to the quake's epicenter, said they did not find any damage when they checked the runways and there were no delays reported.
Comments
Another Pleasanton neighborhood
on Sep 6, 2008 at 7:53 am
on Sep 6, 2008 at 7:53 am
I wasn't in town when the earthquake happened. What effects (if any) did people notice in pleasanton?
another community
on Sep 6, 2008 at 12:05 pm
on Sep 6, 2008 at 12:05 pm
No damage, just slight rolling. Wouldn't even have noticed it if you were moving about...
Downtown
on Sep 6, 2008 at 3:43 pm
on Sep 6, 2008 at 3:43 pm
Loud boom and shaking, scared my kids
Carriage Gardens
on Sep 6, 2008 at 6:56 pm
on Sep 6, 2008 at 6:56 pm
a small shake, my wig fell off...
Dublin
on Sep 6, 2008 at 7:06 pm
on Sep 6, 2008 at 7:06 pm
It was a bit scarey! The couch moved
Carriage Gardens
on Sep 7, 2008 at 4:34 pm
on Sep 7, 2008 at 4:34 pm
It got so shaky shaky I almost got thrown off a porch.
Carriage Gardens
on Sep 7, 2008 at 4:35 pm
on Sep 7, 2008 at 4:35 pm
got henry?
Dublin
on Sep 9, 2008 at 11:32 am
on Sep 9, 2008 at 11:32 am
It was my first time feeling one since I am from South Africa...it was quite a shake but for such a short time that I didnt even realise that it was a tremor. My hubby was asleep and when I woke him up he didnt know about it...
Another Pleasanton neighborhood
on Sep 9, 2008 at 11:12 pm
on Sep 9, 2008 at 11:12 pm
I was sitting at a table in Fuddruckers in Dublin, my chair was on an uneven surface, and it started wobbling back and forth. I knew it was an earthquake, but my husband who was standing up right next to me, felt nothing. He was talking to me, and I kept saying--do you feel that? My chair is shaking!--and he just ignored me and kept talking. I told him--I'm going to prove to you it was an earthquake when we get home and go on the computer.
Ridgeview Commons
on Oct 25, 2008 at 8:38 am
on Oct 25, 2008 at 8:38 am
At me such question
I can not change the menu in Windows, it looks on new why that....
Help to adjust... At me of a Window 98
Ridgeview Commons
on Apr 28, 2017 at 7:35 pm
on Apr 28, 2017 at 7:35 pm
Due to repeated violations of our Terms of Use, comments from this poster are automatically removed. Why?