A swarm of at least six earthquakes reaching up to magnitude 2.9 rattled San Ramon near San Francisco, the U.S. Geological Survey reports. The other quakes in the Saturday, Dec. 13, swarm ranged from magnitude 1.3 to 2.3, according to the USGS.

San Ramon has been hit by multiple quakes over the past four days, including magnitudes 2.9, 2.3, and 2.2 on December 13, a 2.8-magnitude quake on December 14 and 2.4 and 2.1 on December 15. There were dozens of other smaller tremors. Read More | San Jose earthquake: Massive jolt in California; tremors in Hollister, Salinas and Dublin

On Monday morning, around 30 minor earthquakes erupted in a swarm near the Geysers geothermal field south of Clear Lake. The day before, seven quakes rattled Sonoma County, including a 4.0 quake. The recent uptick isn’t out of the ordinary, according to U.S. Geological Survey seismologist Susan Hough.

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

Residents in Nevada woke up to a shocking 5.9 magnitude earthquake alert, but after the panic settled, the whole thing turned out to be a fake quake alert sent by USGS.

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 ShakeAlert system that warns about imminent shaking arriving from earthquakes sent a false alarm across California on Thursday morning for a magnitude 5.9 temblor that did not happen.