UPDATE: A third earthquake was detected at 3:08 PM near Seven Trees in San Jose, CA, very close to the epicenters of the two shakes from this morning. The U.S. Geological Survey detected a magnitude of 3.6 on the Richter scale.

San Francisco and the Bay Area at-large was rumbled by a 5.1 magnitude earthquake with an epicenter 12 miles east of San Jose, according to the U.S. Geological Survey.

The quake occurred at 11:42 a.m. on October 25, according to the USGS. It was followed by a 3.1 magnitude aftershock, which occurred at 11:47 a.m. According to the USGS, the earthquake occurred along the Calaveras Fault.

The San Francisco Fire department tweeted that there was no damage in The City reported at the time. 

The earthquake, however, brought all BART trains to a momentary standstill. 

"Due to the earthquake, trains are holding for 5 minutes and will be followed by inspections. Expect major delays systemwide while we follow our safety procedures," tweeted the transit agency. 

By 11:55 a.m., the trains began moving again at slower speeds, which caused delays of about 12 to 15 minutes for most trains. 

The California Governor's Office of Emergency Services is actively coordinating with local authorities in the region to evaluate any preliminary damage or issues created as a result of the earthquake and provide any assistance that is needed from the state level, Cal OES wrote in a tweet.  

Check back for updates.   

jsalazar@sfexaminer.com

@jamesbewriting