Aftershocks by the thousands jar Southern California, with 70 topping 4.0 magnitude

A 4.2-magnitude aftershock rattled Southern California near Ridgecrest early Monday morning, the U.S. Geological Survey reported.

The quake struck 5.6 miles east of Coso Junction in Searles Valley at 1:38 a.m., according to the USGS.

Thousands of aftershocks have rattled the region since two of the strongest Southern California quakes in years hit July 4-5, KNBC reported.

At least 70 of those aftershocks have reached 4.0 magnitude or higher on the moment magnitude scale, the Los Angeles Times reported.

Quakes below 4.0 magnitude are rarely felt by people, while those up to 5.0 magnitude may be felt indoors and may cause slight damage, the USGS says.

The moment magnitude scale is the modern evolution of the Richter Scale formerly used to measure temblors, McClatchy reported.

A 6.4-magnitude quake hit near Ridgecrest at 10:33 a.m. July 4, followed by a 7.1-magnitude quake at 8:19 p.m. July 5, the USGS reported.

The second quake caused fires, power outages and some damage in the Searles Valley area around Ridgecrest, near the Mojave Desert.

Authorities say a 56-year-old man found several days later crushed beneath a Jeep in Pahrump, Nevada, likely died as a result of the first quake, McClatchy reported.

By July 8, more than 3,000 aftershocks had already rattled the Searles Valley region, KNBC reported.

In all, scientists expect more than 34,000 aftershocks from the two quakes over the next six months, the Los Angeles Times reported.

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Don Sweeney has been a newspaper reporter and editor in California for more than 25 years. He has been a real-time reporter based at The Sacramento Bee since 2016.