Large earthquake in Nevada desert felt in Sacramento, throughout California

A large earthquake struck in a remote area of western Nevada early Friday. The quake — initially reported by the U.S. Geological Service at a magnitude of 6.5 — could be felt in Sacramento, more than 300 miles away.

The quake was reported just after 4 a.m. near Tonopah, Nev., about 100 miles east of Yosemite National Park and roughly halfway between Reno and Las Vegas.

Twitter was full of people reporting they felt the earthquake in Sacramento, Fresno and the Bay Area. It was followed by a series of small aftershocks, the USGS reported.

Friday’s earthquake was the same magnitude as a 6.5 earthquake that hit the Boise, Idaho, area on March 31.

Some of the most recent earthquakes and aftershocks felt in Northern California came in March and shook the coast, with magnitude 4.8 and 5.8 quakes striking about 50 miles west of Petrolia in Humboldt County.

According to a previous story in The Bee, while the likelihood of a significant earthquake in Sacramento is considerably lower than in the Bay Area, that doesn’t mean it can’t occur, said Richard Armstrong, a Sacramento State professor who studies earthquake engineering.

“It’s just less likely,” he said.

Still, even if Sacramento doesn’t face the same earthquake threat as other cities such as San Francisco or Los Angeles, “it has felt the effects of earthquakes in the past and likely will in the future,” according to California Geological Survey spokesman Don Drysdale.

For example, if a major earthquake were to hit near the city, the shaking could loosen sandy soil deposits, allowing water to penetrate and saturate the earth. The liquified soil could then lose its strength, cracking and moving underneath structures like levees and buildings, Drysdale said.

In downtown Sacramento and other areas near the American River or the Sacramento River, most of the land has young sedimentary river deposits and a high water table.

“Those are two of the three major ingredients that create liquefaction,” Drysdale said in an email. “The only missing ingredient for liquefaction in Sacramento is earthquake shaking.”

AT THE EPICENTER

The cracked main highway between Las Vegas and Reno reopened 10 hours after the predawn quake that a researcher called the largest to strike the remote area of western Nevada in 65 years.

No injuries were reported, but officials said goods tumbled from market shelves, sidewalks heaved and storefront windows cracked. Nevada Highway Patrol photos showed cracks on U.S. 95 before crews repaired them about 35 miles west of Tonopah. A detour to State Route 360 had added more than 20 miles to motorists’ trips.

The vast open range east of the snow-capped Sierra Nevada is seismically active, said Graham Kent, director of the Nevada Seismological Lab at the University of Nevada, Reno. He ranked Friday’s event with twin December 1954 earthquakes at Fairview Peak and Dixie Valley. Kent said those temblors were magnitudes 7.1 and 6.8, respectively.

Friday’s temblor was centered about 4.7 miles deep, the U.S. Geological Survey said, and dozens of aftershocks were recorded. Kent said a 5.1 magnitude aftershock struck about 30 minutes after the initial quake.

State troopers and sheriff’s patrols from Esmeralda and surrounding Mineral and Nye counties checked highways for possible damage. A sheriff’s dispatcher in the historic mining boom town of Goldfield said the 112-year-old Esmeralda County Courthouse escaped damage.

Nye County sheriff’s Capt. David Boruchowitz reported no damage at the Mizpah Hotel and Clown Motel, two landmark businesses in Tonopah, a mining hub about halfway between Las Vegas and Reno.

Keith Hasty, a Tonopah gas station employee, told the Las Vegas Review-Journal that groceries were shaken off shelves and that residents said their televisions shook.

Nye County spokesman Arnold Knightly reported broken storefront glass, stress cracks on asphalt streets, loose hanging signs, items knocked off shelves and minor lifting of sidewalks.

“Overall, everything appears to be sound at this point,” Knightly said. “ ‘’However, we have learned that other than obvious earthquake damage some damage is discovered later.”

SHAKING IN SACRAMENTO?

Sacramento County could experience strong shaking during a large earthquake, but the resulting damage would be less than areas near major active faults such as the Bay Area.

Buildings specifically designed to withstand earthquakes and other “well-built” structures would likely survive a major earthquake, according to the Federal Emergency Management Agency. Shoddier buildings may have considerable damage or collapse entirely.

In 2008, the U.S. Geological Survey created animations of different earthquake scenarios along the Hayward Fault, a major active fault that runs under East Bay, including Berkeley, Oakland and San Jose.

Simulations of a strong magnitude-6.8 earthquake or more show Sacramento would likely experience significant shaking – the kind that would awaken most, and cause some dishes and windows to move or break, according to the U.S. Geological Survey.

But smaller earthquakes are far more common, and those are usually experienced without an issue in Sacramento.

Sacramentans rarely report feeling shaking beyond vibrations similar to a truck passing by, according to the U.S. Geological Survey’s Did You Feel It? crowdsourcing website.

A smaller, 3.2-magnitude earthquake was also reported by the USGS Friday south of Susanville. The quake was relatively light in terms of intensity, according to USGS data. Very few respondents reported feeling tremors, although at least one report came all the way from Reno.

This story was originally published May 15, 2020 at 5:15 AM.