Swarm of aftershocks follows 4.2-magnitude quake north of San Francisco, USGS says

A shallow 4.2-magnitude earthquake shook the Northern California coast north of the San Francisco Bay Area at 4:57 a.m. local time Tuesday, June 28, the U.S. Geological Survey reports.

The quake, less than a mile deep, hit west-northwest of Cobb, according to the USGS. Dozens of people from as far away as Santa Rosa and Petaluma reported feeling the tremor to the agency.

A slew of aftershocks below 2.0-magnitude followed the early-morning temblor.

Cobb is a community of about 800 people in Lake County about 15 miles southwest of Clear Lake.

Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.

Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech. Quakes below 2.5 magnitude are seldom felt by most people.

This story was originally published June 28, 2022 at 6:14 AM.