Ongoing ‘swarm’ of small earthquakes in Nevada has experts’ attention

An ongoing swarm of dozens of small earthquakes near Reno is a reminder that the Silver State is “earthquake country,” but Nevadans shouldn’t take that as a sign that a big one is definitely coming, an expert said.

“The swarm is it’s definitely a reminder that we live in earthquake country, but it doesn’t mean for certain that a bigger earthquake is going to happen, although it certainly could,” said William Savran, network manager at the Nevada Seismological Laboratory based at the University of Nevada, Reno.

The ongoing swarm of quakes in the Spanish Springs area, northeast of Reno, started at the beginning of October, Savran said.

The swarm has so far included a magnitude 3.6 quake on Monday, a magnitude 3.5 on Thursday, and a magnitude 3.1 on Friday, he said. A magnitude 3.5 would feel like a big jolt, with not too much lingering shaking, he said.

“As far as everything I’ve seen, I don’t think there’s a very specific out-of-the-ordinary cause,” Savran said. “There’s faults all over the state, and earthquakes happen all over the state.”

Savran said it’s the biggest swarm to happen near Reno in some time. He said the last notable Reno-area earthquake swarm was the Mogul-Somersett swarm in 2008, which happened near the suburbs of Mogul and Somersett.

He said seismic activity is always happening in the area, but there is just more of it now.

A magnitude 6 earthquake happened on Feb. 21, 2008, near Wells in northeast Nevada, but wasn’t part of the Mogul swarm, Savran said.

The quake damaged hundreds of homes and about 20 to 25 buildings in the town’s historic district, but no serious injuries were reported.

Earthquake swarms are not unusual for Nevada, Savran said.

Another swarm, the 2014-2015 Sheldon swarm in the northwest corner of Nevada, had “orders of magnitude more earthquakes and lasted for over a year,” Savran said in an email.

As part of that swarm, 20 earthquakes occurred with greater than magnitude 4, with 200 greater than magnitude 3.

That’s much stronger than the ongoing swarm, which has had three quakes measuring more than magnitude 3.

He also pointed out another swarm near Carson City in 2020, and the swarm near Hawthorne in 2011.

In 2020, the magnitude 6.5 Monte Cristo earthquake struck about 35 miles west of Tonopah, damaging sections of U.S. 95.

On an average day, about 10 earthquakes happen across Nevada, but they’re mostly small, Savran said.

In the past week, 40 earthquakes have happened around the state, Savran said. He said it’s a little higher than average, given the swarm of earthquakes.

“Pretty much any mountain range that you see in Nevada has some faulting associated with it, so there’s a pretty large potential for earthquakes here,” Savran said. “We have the third-most earthquakes in the country behind Alaska and California.”

As such, Nevada residents should always be prepared for an earthquake. The Nevada Seismological Laboratory’s website features a preparedness page that lists resources, including a handbook described as a “Nevadan’s guide to preparing for, surviving, and recovering from an earthquake.”

Contact Brett Clarkson at bclarkson@reviewjournal.com.