Earthquake shakes Boise with 6.5 magnitude that could be Idaho’s second-strongest ever

An earthquake shook Boise and the Treasure Valley at 5:52 p.m. Tuesday, according to the U.S. Geological Survey.

The shaking lasted for 20-30 seconds, with a small pause, at a home in East Boise and at the Idaho Statesman building on the Boise Bench.

The U.S. Geological Survey pegged the earthquake at 6.5 magnitude, with an epicenter in the mountains northwest of Stanley and 45 miles west of Challis. The quake hit near the northern-most turn in Idaho 21 between Stanley and Lowman, or 73 miles northeast of Meridian.

There were at least 20 aftershocks, according to USGS, with a magnitude-4.6 tremor giving parts of Boise a strong, brief shake at 6:27 p.m. A 4.4 struck at 8:09 p.m.

Stanley Mayor Steve Botti told the Idaho Statesman about 8:45 p.m. that he hadn’t seen any damage but the town was “still surveying for damage.”

“Stuff was flying all over the place,” Botti said earlier. “I was upstairs and I tried to walk down the steps and I couldn’t because it was shaking too much.”

Officials in the Treasure Valley also had encouraging early news.

“We don’t have any reports of damage just yet,” Haley Williams of the Boise Police Department said shortly after the first quake.

“We haven’t sent any first responders out — police or fire,” said Stephany Galbreaith, of the Meridian Police Department.

Boise Mayor Lauren McLean said that “first responders are out doing building checks downtown. We’ve already done a scan of all of our public works facilities and they all look good.”

According to past Idaho Statesman research, the magnitude-6.5 quake would be the second-largest in Idaho history if it stands (the number often is adjusted with more information). The Borah Peak earthquake in 1983, which was a magnitude 6.9, killed two people in Challis near the quake’s epicenter. The second-largest on the books now is a three-way tie at 5.8 from 1983-84.

The five strongest previous Idaho earthquakes were all in the Challis area.

Expect more earthquakes in the days to come, USGS says. There’s a 48% chance of a magnitude-5.0 quake or higher, its forecast says.

“According to our forecast, over the next one week there is a 4% chance of one or more aftershocks that are larger than magnitude 6.5,” the USGS forecast says. “It is likely that there will be smaller earthquakes over the next one week. … Magnitude 3 and above are large enough to be felt near the epicenter. The number of aftershocks will drop off over time, but a large aftershock can increase the numbers again, temporarily.”

Local resident Anna Eberlin sent the Idaho Statesman a photo of a mirror that crashed to the floor in her house.

“It scared my kids and me half to death,” she said. “Everyone is OK after some tears and nervous excitement about their first earthquake.”

Typically, Idaho earthquakes occur in the central and southeast parts of the state. Recently, a swarm of low-magnitude quakes rumbled across parts of Idaho, Utah and California.

Two earthquakes rattled the Boise area in the mid-1940s, according to the Idaho Geological Survey. Another in 1916 “wrecked several brick chimneys at Boise and sent residents rushing into the street.”

Central Idaho has seen its share of seismic activity in recent years. The region saw swarms of earthquakes in December 2015; December 2014 to January 2015; December 2014; and April to May of 2014. Those included a 5.0 earthquake on Jan. 3, 2015, and a 4.8 earthquake on April 13, 2014.

There were immediate reports that Tuesday’s earthquake was felt in Coeur d’Alene, Twin Falls and Hailey in Idaho; Spokane, Washington; Utah; and Missoula and Bozeman in Montana.

“I am from Florida and we have always had hurricanes growing up, but I had never been in an earthquake,” said Kurt Wisehart, of Boise. “This was the first time for me, which is why I walked out ’cause this is weird. Like, what’s everyone do?”

Meridian resident Zach Borman said he and his wife experienced nausea after the quake.

“Felt a bit longer than a minute,” Borman said. “While minding our social-distancing business, the house started a low rumbling. I assumed it was a heavy wind, or some sort of issue with our air conditioning, but my wife and the dogs were both reacting to it and it just kept going.

“My first thought when I realized it was probably an earthquake was: ‘Wow. More stacked on top (of the coronavirus pandemic)? Way to add insult to injury.’ ”

Spencer Tangen of the National Weather Service in Boise said it might not be unusual to feel aftershocks with an earthquake that size. So did McLean.

“I’d just like the community to know that there is likely a very real possibility with a quake of that size that you’ll feel more,” McLean said.

Intermountain Gas spokesman Mark Hanson said the company had received some calls from people smelling gas, and technicians were responding and assessing. He didn’t have further information.

Idaho Power immediately began inspecting its 17 hyrdoelectric plants across Idaho after the earthquakes, spokesman Jordan Rodriguez said. That was the main infrastructure concern, he said. The dams are mostly along the Snake River.

“We have completed onsite inspections at each of our power plants and found no damage,” Rodriguez texted Tuesday night. “In addition, no power outages or system problems were reported as a result of the quake.”

The Ada County Sheriff’s Office tweeted a request for people to stop spreading “false online rumors” about damage to Lucky Peak Dam. A message left with the U.S. Army Corps of Engineers, which manages the Lucky Peak Dam and Lake area, wasn’t immediately returned.

Suez Water Idaho also didn’t immediately return a message.

Savannah Brehmer, spokeswoman for Federal Emergency Management Agency region 10, which includes Idaho, Washington, Oregon and Alaska, said you should not attempt to run outside or hide in a doorway during an earthquake.

”Dropping, covering and holding on is the best action to take as soon as you realize an earthquake has hit,” Brehmer said. “That’s what’s going to keep your most precious organs safe from potential injury.”

Reporter Michael Lycklama, Breaking News Editor Jim Keyser and special correspondent Rocky Barker contributed.

Editor’s note: This story has been updated to correct the spelling of Haley Williams’ name.