A 6.5 magnitude earthquake hit southern Idaho around 5:52 p.m. Tuesday, but caused no significant damage as of latest reports.
The quake, which lasted for 23.5 seconds, hit 19 miles northwest of Stanley — or about 78 miles northeast of Boise, according to U.S. Geological Survey. It was felt throughout Idaho and in seven surrounding states, according to USGS’ Community Internet Intensity Map.
A 4.6 earthquake aftershock followed at 6:27 p.m., and before midnight at least another six aftershocks were recorded. Local and state police did not report any damage or injuries Tuesday evening.
The strength of the earthquake was at the high end of the range for the area and follows a pattern of big quakes every two decades or so, Lee Liberty, a geophysics professor at Boise State University, told the Idaho Press.
“What I think it is is the Sawtooth Fault north of Stanley,” he said.
Downtown Boise sits on sediments that amplify the shaking, Liberty noted, but he didn’t expect the quake to have caused much damage in the area because it was too far away and not big enough to cause any real issues.
“The problem will be in the mountains, where there was heavy rain and snow earlier today, so the chances of mudslides and avalanches are pretty real,” he said.
USGS Seismologist Paul Earle said that according to the Survey’s aftershock model, there is a 10% chance of a magnitude 6 or greater earthquake happening in the same area in the next week and a 50% chance of a magnitude 5 or greater quake striking in that same time frame.
“We’ll keep an eye on it,” he said.
Harvey Dale has owned a house seven miles south of Stanley across from the fish hatchery for 10 years and has been full-time resident since January 2018.
“There was lots of rumbling,” he said. “But we didn’t lose any glass or have any broken windows. We’ll have to wait a month or so to see if we have any cracks in the siding or the foundation.”
Dale’s nearest neighbor lives about a mile away but as of 7:30 p.m. Tuesday, Dale said he hadn’t heard of any injuries or any major structural damage to the community’s buildings.
It was felt far south as Franklin County and in northern Utah.
Preston resident Jill Durrant said she was sitting in her kitchen and the pans hanging on her wall started swaying a little.
“I felt just a little bit like I was on a boat and my brain was sloshing around. Not huge, but enough to think it was weird,” she said.
Her mother, a couple miles away felt it as well.
In Logan, resident Bri Johnson reported experiencing the earthquake while taking a bath.
The bath water was sloshing for no apparent reason, she said. “Also, I had a glass of water sitting on the side of the tub, and that’s what really made me notice because it was also sloshing.”
The largest earthquake in Idaho history was the 6.9 magnitude Borah Peak earthquake in 1983, the Bozeman Daily Chronicle reports.
Marcus Smith, an emergency room health unit coordinator at St. Luke’s Wood River Medical Center, said the hospital, about 65 miles south of the epicenter, shook but the quake didn’t interfere with the treatment of any patients. The hospital in Blaine County is on the front line of Idaho’s coronavirus outbreak, in a region with the highest per-capita rates of known COVID-19 cases in the nation outside of New York City and surrounding counties.
“It felt like a wave going through the ground, so I knew right away what it was. It just felt like waves going through the ground,” he said.
The earthquake is added stress during an already stressful time for the region, but Smith said everything seemed fine, for now. “Until the next one, I guess,” Smith said. “I mean, that’s what we do. We’re all good.”
Brett Woolley, a restaurant owner in Stanley, said he heard earthquake coming before he felt it.
“I heard the roar, and at first it sounded like the wind but then the roar was tremendous,” Woolley said about 10 minutes after the earthquake. “The whole house was rattling, and I started to panic. I’m sitting here perfectly still and the water next to me is still vibrating.”
The USGS also recorded two small earthquakes near West Yellowstone on Tuesday, according to the Chronicle. The tremors had magnitudes of less than 3.