‘Unusual flurry’ of earthquakes shakes near Idaho mountain town

STANLEY (Idaho Statesman) — More than a dozen earthquakes have rattled Central Idaho since Sunday morning in an “unusual flurry” of activity, according to Idaho state geologist Claudio Berti.

Berti, who is the director of the Idaho Geological Survey, told the Idaho Statesman that researchers have been keeping a close eye on the seismic activity, which originated from the Basin Butte area north of Stanley.

The geologist noted the earthquakes are not coming from the same area as the magnitude-6.5 earthquake that occurred nearby in 2020 and shook much of the state. That quake, which originated near the Cape Horn Mountain in the Boise and Salmon-Challis national forests, was the second-largest in recorded history and was felt by many Boise residents.

Berti said the previous seismic activity likely made it possible for the U.S. Geological Survey to detect the recent tremors, which have ranged in magnitude from 2.5 to 3.2. Geologists installed earthquake monitoring tools in Central Idaho after the 2020 earthquake, he told the Statesman.

Though small, Berti said the earthquakes are likely strong enough to be felt by people in Central Idaho, particularly if they’re indoors.

Idaho is one of the most seismically active states in the country, and Central Idaho has gained prominence in recent years as a particularly active area. Berti said numerous faults are in the area, and there’s still a lot of research to be done. Clusters of earthquakes like the ones currently happening have helped teach researchers what’s going on below the earth’s surface, he said.

“When we get one single (earthquake) event somewhere in the middle of nowhere, it is hard to make any sense of it,” he said. “As we see a number of those earthquakes that come one after another, concentrated or focused in some specific region, the alignment of those individual earthquakes, we say, illuminate a fault plane.”

The clusters of earthquakes can’t tell experts what will come next. Berti said there are diverging schools of thought on whether increased seismic activity predicts a larger upcoming earthquake or makes one less likely as energy is released in the smaller quakes.

Regardless, Berti said, it’s a good reminder of Idaho’s earthquake risk. He encouraged people to be prepared for potential hazards by being aware of earthquake safety procedures.