Another 4.7 magnitude earthquake hit northwest Nevada, tying the largest in a yearlong swarm recorded at the Sheldon National Wildlife Refuge near the Oregon and California borders.
The quake hit the area about 6:55 a.m. Monday, according to the University of Nevada's Reno Nevada Seismological Laboratory. At least five aftershocks of magnitude 2 or greater were recorded in the three hours that followed.
Mickey Cassar, a technician who tracks earthquakes at the lab, said there haven't been reports of injuries or damage.
The depth of the rupture was about 6 miles below ground, which means most people wouldn't have felt it. However, there were reports from residents in Fallon and Gerlach in Nevada, as well as in the California communities of Redding, Fort Bidwell, Alturas and Cedarville. There were also reports in Adel, Lakeview and Silver Lake, Oregon, according to the United States Geological Survey's Earthquake Hazards Program.
The Nevada earthquake marks the second 4.7 magnitude earthquake in the Sheldon wildlife refuge's yearlong swarm. One recorded on Nov. 6 was the largest one to hit since the thousands of earthquakes started in July 2014.
Seismologists have called the long-lasting swarm unusual. There was a flare-up that started in mid-July that had, as of August, brought the total to more than 5,600 earthquakes.
Cassar said there's no immediate indication of what's next given the latest quake.
"We don't have any conclusions that are being drawn," he said. "Nevada's kind of known for these kinds of long trending swarms."
Officials have said that a swarm of thousands of little earthquakes could eventually lead to a big one.
Three magnitude 7.0 earthquakes each century and one magnitude 6.0 or larger each decade are expected in Nevada. The last "big one" was the Dixie Valley/Fairview Peak event east of Fallon that hit in 1954 with two magnitude 7 earthquakes that came four minutes apart.
In May, a magnitude 4.8 earthquake struck near the town of Caliente in rural southern Nevada, which temporarily shut down a busy interchange and shook buildings more than 100 miles away in Las Vegas.
Nevada is the third most seismically active state in the country behind California and Alaska.