Dozens of aftershocks pummel Northern California coast following 6.4 quake

A 6.4-magnitude earthquake off the Northern California coast has spawned dozens of large aftershocks, some inland, ranging up to 4.8-magnitude, the U.S. Geological Survey said.

The 6.4-magnitude temblor struck around 2:34 a.m. Tuesday, Dec. 20, and was centered 13 miles west of Fortuna, The Sacramento Bee reported. Thousands of people reported feeling the earthquake.

There were no immediate reports of injuries, but the quake 3 miles off the coast did cause some damage and cut power to homes along the Humboldt County coast.

By 8 a.m., more than 40 aftershocks measuring more than 2.5 magnitude had been detected. More than 20 were above 3.0 magnitude.

The largest aftershock, at 4.6 magnitude, struck at 2:39 a.m. on land near Rio Dell, a town of about 3,600 residents along the Eel River and 10 miles inland from the original epicenter. Nearly 100 people reported feeling the aftershock.

The most distant aftershocks recorded as of 6 a.m. include a 3.9-magnitude quake at Willow Creek about 24 miles inland and a 4.2-magnitude quake in the Pacific Ocean about 50 miles northwest of the initial temblor.

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 December 20, 2022 at 6:39 AM with the headline "Dozens of aftershocks pummel Northern California coast following 6.4 quake."