A swarm of at least a dozen earthquakes reaching up to magnitude 3.9 rattled San Ramon near San Francisco, the U.S. Geological Survey reports.

SAN RAMON — A cluster of earthquakes struck the San Ramon area Friday night, continuing a pattern of seismic activity in recent weeks, according to the U.S. Geological Survey. Things kicked off at 7:41 p.m. with a magnitude 2.5 centered 3.1 miles southeast of the city.

Earthquakes have continued to hit California for days at a stretch, with several tremors felt across Bay Area, San Ramon, Hayward, Dublin, Pleasanton on Friday.

CONTRA COSTA COUNTY, CA - According to the U.S. Geological Survey, a 4.0 magnitude quake occurred near San Ramon Friday evening.

California's seismic risk is increasing with supershear earthquakes, which are faster and more destructive than typical earthquakes.

Major quakes in Japan and Alaska along with a spate of smaller earthquakes in California this fall make folks ask, is the Big One near?

The quake came only eight days after three earthquakes shook the area in the course of about 100 minutes. More than 30 quakes also were recorded between midnight and 10:15 a.m. on Dec. 8, according to CalTech’s California Earthquake Center.

California has been hit by an earthquake swarm for the fourth day in a row. Residents have been experiencing earthquake swarms for nearly a week, with the latest hitting on Tuesday, December 16. The US Geological Survey (USGS) reported that a quake with a 3.