3.9 Earthquake Rocks Lamorinda

A strong earthquake shook Lamorinda like a dog with a bone Thursday, toppling teacups and china displays in a few living room curio cabinets and prompting first responders to move their apparatus outside in the event of a more destructive, follow-up temblor.

The USGS seismographic station put the origin of the quake two miles east southeast from Berkeley and said it rolled through the area at 2:41 p.m. The USGS almost immediately downgraded the temblor from a 4.2 shaker to a 3.9 after a data review.

"It was very loud at my house (in Moraga near JM) too," said Patch reader Julie Carlson. "A picture frame tipped over and knocked something else off a shelf - I can't remember the last time that happened. For a split second I thought someone had jumped a curb and slammed a car into my house!"

Moragans reported a single, sustained shock which lasted for a few seconds. The jolt triggered a rash of alarms and a few calls for help from residents whose windows shattered during the shaker. Many Lamorindans reported a single, sustained rolling jolt of about four seconds duration.

There were no reports of major damage though cautionary measures were taken as Moraga-Orinda Fire and Contra Costa County Fire stations as fire crews rolled their engines outside to prevent them from being trapped inside by a larger, more destructive aftershock. Maintanence crews were also seen inspecting BART tracks after Thursday's temblor -- a routine measure taken after a seismic event.

BART trains slowed but were not ordered stopped. It was not immediately known what the track inspections would mean for the afternoon commute. As it happened, the event took place on the same day as the annual Great California ShakeOut disaster drill.

We'll post additional information on this event as we get it.