Multiple small earthquakes struck Northern California within about a minute late Monday night, including two offshore quakes west of the Bay Area, one in the Sierra Nevada foothills and another near the Oregon border, according to the U.S. Geological Survey.
The strongest, a magnitude 3.8 quake, hit at 9:48 p.m. about 35 miles southwest of the Point Reyes coastline, the USGS reported. Around the same time, a magnitude 3.7 quake struck roughly 53 miles southwest of Bonny Doon, off the Santa Cruz County coast.
Moments later, at 9:49 p.m., a magnitude 3.3 quake was recorded about 2 miles southeast of Yreka in Siskiyou County, near the California-Oregon border, according to the USGS. At the same time, a magnitude 3.2 quake struck about 18.6 miles east of Shaver Lake in the Sierra Nevada foothills, the agency said.
All four earthquakes were automatically detected by the Northern California Seismic System. The two offshore quakes were recorded at shallow depths of about 4.9 kilometers, while the Yreka quake occurred at a depth of about 3.5 kilometers. he Shaver Lake-area quake was recorded at a depth of about 3 kilometers.
As of late Monday night, there were no immediate reports of damage or injuries.
Preliminary ShakeMap data indicated light shaking offshore, with the Point Reyes event reaching an intensity of II and the Bonny Doon quake registering at intensity I. No intensity was immediately listed for the Shaver Lake-area quake.
The Yreka quake also did not yet have a reported intensity level in the available data.
Based on their locations, the four quakes do not appear to be directly related, occurring hundreds of miles apart in different seismic regions.
Seismologists may revise the earthquakes’ magnitudes, depths and other details as more data becomes available.