Dozens of strong aftershocks follow Sierra Nevada earthquake in Northern California

More than 30 aftershocks, some over 4.0 magnitude, continue to rattle Northern California following a 6.0-magnitude quake in the Sierra Nevada mountains.

The initial quake struck at 3:49 p.m. Pacific time in the Little Antelope Valley about four miles south of Coleville in Mono County, about 150 miles east of Sacramento.

The U.S. Geological Survey had recorded dozens of sizable aftershocks of 2.5 magnitude or more, over 30 in all, by 6 p.m., with more continuing to roll in.

One, near Markleeville, reached 4.6 magnitude, with others falling in the 3.0 to 4.0 range.

Seismologist Lucy Jones wrote on Twitter that such aftershocks are expected with large earthquakes in the area.

“As is common in this region, there are a lot of aftershocks — 10 above M3 in the first hour,” she wrote on Twitter.

Jones said there’s a 5% to 10% chance that an aftershock could be larger than the initial quake, but a 90% chance none will exceed the 6.0-magnitude quake.

The U.S. Geological Survey seconded that, predicting a 5% chance of a larger aftershock in the next week, with a series of up to 420 aftershocks of 3.0 magnitude or lower.

The number of aftershocks will drop off over time, but could spike with another large quake.

The USGS put the odds of an aftershock registering 7.0 magnitude or higher at 1-in-200.

“No one can predict the exact time or place of any earthquake, including aftershocks,” the USGS warned.

Magnitude measures the energy released at the source of the earthquake, USGS 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. Earthquakes of 5.5 to 6.0 magnitude may cause slight damage to buildings and other structures.

This story was originally published July 8, 2021 at 6:26 PM with the headline "Dozens of strong aftershocks follow Sierra Nevada earthquake in Northern California."