Earthquake: 5.9 quake centered between Yosemite and Mammoth

Shaking felt as far west as San Francisco. The preliminary epicenter was just west of the town of Walker, where fewer than 1,000 people live, in the northern edge of Mono County. The epicenter was about 70 miles northwest of Mammoth Mountain.
A magnitude 5.9 earthquake struck California’s Eastern Sierra Nevada Thursday, sending strong shaking through a rural mountainous region and light shaking across much of Northern California.
The preliminary epicenter was just west of the town of Walker, Calif., where fewer than 1,000 people live, in the northern edge of Mono County. The epicenter was about 70 miles northwest of Mammoth Mountain.

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The earthquake was reported at 3:49 p.m. Weak to light shaking was felt by some people as far away as Lake Tahoe, Sacramento, San Francisco and San Jose, according to reports by seismic instruments and people filing reports to the U.S. Geological Survey’s Did You Feel It? survey — but it was not uniform, and some people in the East Bay and San Mateo County felt no shaking at all.
One person who said he was tweeting from Daly City posted an image of a light fixture swinging gently.
Traffic on a section of U.S. 395 has been shut after reports of rockslides in northern Mono County, Caltrans said.
There were no immediate reports of significant damage. KGO-TV quoted people in Walker, Calif., saying the shaking was enough to toss cups off shelves.
The quake left a short but noticeable impression among people working in and around the historic state Capitol building."That was a heckuva earthquake to hit the Capitol,” state Sen. Mike McGuire (D-Healdsburg) posted on Twitter.
USGS instrumentation said light shaking was detected in Sacramento, as defined by the Modified Mercalli Intensity Scale as enough to rattle dishes and windows.
The Democratic lawmaker was in the building to chair a legislative committee hearing, while most lawmakers had departed after the conclusion of morning floor sessions.
Members of The Times’ Sacramento bureau were conducting a virtual staff meeting by Zoom when the earthquake struck. Those in the eastern reaches of Sacramento County and in Placer County felt it first, with the waves spreading a few seconds later to the downtown areas of the capital city.
A flood of posts and appeared on social media discussing not only the earthquake but the rarity of such an event in Sacramento, a city far away from many of the state’s most active fault lines.
There are a number of active faults in this region of California in what’s called the Walker Lane system, said Keith Knudsen, deputy director of the USGS’ Earthquake Science Center.
“There is tectonic slip that goes up the east side of the Sierras, and there have been a number of historical earthquakes of this size or bigger in the last few decades. So it’s not a big surprise that it happened here,” Knudsen said.
The Sierra Nevada are underlain by cold, hard rock, and “and they ring like a bell when an earthquake happens there. So they transmit the earthquake energy really well,” Knudsen said, which may explain why the earthquake was felt so widely across California.
An average of five earthquakes with magnitudes between 5.0 and 6.0 occur per year in California and Nevada, according to a recent three-year data sample.
Did you feel these earthquakes? Consider reporting what you felt to the USGS.
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The first version of this story was automatically generated by Quakebot, a computer application that monitors the latest earthquakes detected by the USGS. If you’re interested in learning more about the system, visit our list of frequently asked questions.
This story originally appeared in Los Angeles Times.