Earthquake swarm rattles central Nevada near Tonopah along newly identified fault

A swarm of earthquakes has been rattling a remote stretch of central Nevada near Tonopah, including a magnitude 4.0 quake that hit near Warm Springs Tuesday morning.

Seismologists said the activity is typical for Nevada, where clusters of earthquakes can flare up in a concentrated area. “This is a very Nevada-style earthquake sequence. We have these a lot where we just see an uptick in activity in a certain spot,” said Christie Rowe, director of the Nevada Seismological Lab.

The latest magnitude 4.0 quake struck east of Tonopah near Warm Springs. The largest earthquake in the swarm so far has measured a 4.2.

What has stood out to researchers is the fault involved. Rowe said the earthquakes are occurring along a fault stretching along the southern edge of the Monitor and Antelope ranges — and that it was previously unknown to scientists. “We didn’t know this fault was there. It’s a new fault to us — not to the Earth, obviously — but it was previously unknown,” Rowe said.

For now, the earthquakes have remained moderate. Rowe said the lab would not deploy additional temporary sensors unless activity increases to around a magnitude 5 or greater.

Seismologists said they are continuing to watch the swarm closely as Nevada works to bring the ShakeAlert early warning system to the state. The program, already active in neighboring states, can send cellphone alerts seconds before shaking arrives. “For me, it’s a really high priority. That distance to the faults gives us enough time to warn people — and that can make a big difference in reducing injuries and damage,” Rowe said.

Seismologists encouraged anyone who feels shaking to report it through the U.S. Geological Survey’s “Did You Feel It” system, saying even small quakes can help scientists better understand Nevada’s seismic activity.

Experts said the swarm is worth monitoring but is not cause for alarm. They noted that earthquakes like the 5.8 that hit near Yerington in December 2024 typically happen in Nevada about every eight to 10 years, and said they will continue monitoring the current activity closely.