Strong Earthquake Felt Throughout Bay Area

SAN FRANCISCO BAY AREA, CA — An earthquake with a preliminary reading of 5.1 was felt throughout Northern California at 11:42 a.m. An aftershock of 3.1 was felt at 11:47.

The epicenter was 12.1 miles east of San Jose, in Santa Clara County but it was felt by people as far away as Nevada, According to the United States Geological Survey Shake Map.

No information is available about injuries or damage.

BART held trains for 5 minutes following the earthquake, and then resumed service at reduced speeds as tracks were inspected. No damage was found. Service has returned to normal. Caltrain also inspected its tracks following the quake.

According to the USGS, the earthquake began in the vicinity of the Calaveras Fault.

The agency reports on its website, "The Calaveras Fault is a mostly right-lateral, strike-slip fault. The 2003 Working Group Report divided the fault into three segments. The northern segment of the Calaveras Fault is virtually locked and this segment of the fault creeps at a rate between 2 and 3 mm/yr. At the southern end of its central stretch it creeps at about 14 mm/yr dropping northward to about 6 mm/yr (0.24 inch/yr) of creep at its intersection with the Hayward Fault."

The last notable earthquake on the Calaveras Fault was in October 2007, when a M5.4 Alum Rock earthquake ruptured on the south end of the fault. Tuesday's earthquake was 9.1 miles from Alum Rock.

Residents rushed to Twitter to comment on the earthquake, and to make fun of themselves and others for turning to social media in droves to check on the earthquake. A few people posted videos of lamps swaying, but nothing significant.

Did you feel it?

You may report it to the USGS for tracking purposes.

Report your response to USGS Did You Feel It.

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