Some people in the Helena Valley felt the earth move for the second time in a week last night, after a mild earthquake hit west of Helena.
The 3.8 magnitude quake hit at 9:02 p.m. just outside the community of Avon in Powell County, and was recorded at a depth of about 12.5 miles.
It was centered 3.2 miles southeast of Avon, about 25 miles west of Helena, and 39 miles north of Butte.
There were no injuries, and no serious damage reported, but it was felt by scores of people, according to the U.S. Geological Survey website.
People reported feeling it in Avon, Garrison, Butte, Lincoln, Helena, Clancy, Canyon Creek, Deer Lodge, and East Helena.
Amanda Lytle felt it, and said, "I was watching TV and the house shook. It felt like something hit the house.”
Lytle says she’s lived near Avon her whole life, but never remembers feeling a quake before.
She said, “I never knew that there would be an earthquake here. I didn’t know there were faults around this area.”
Among the responses received by MTN News via Facebook:
- John Cech: YES…in Clancy about 9 miles south of Helena..our house shook, doors rattled, and it very briefly sound like a train nearby.
- Wendy Rae: Did anyone else just feel that? The house shook & my neighbor about a 1/4 mile away said her house shook, too. We’re in Clancy.
- Theresa Parvinen: YEP! Sitting watching TV.. house shook. Couch moved.
- Leisa Radley: My house moved, jingled my plates, scary.
- Jodi Aschim: Yep, here in SunHaven, felt like someone ran into my house.
- Elois Myers Johnson: Did feel it in East Helena. Thought I was having a dizzy spell, but I was sitting down, so knew it was a quake.
- Kim Johnson: Sounded like a large boom, house windows rattled and house shook.
- Rhonda Simmons: Yes, rumbled and rolled out here in Birdseye.
Sunday’s quake came less than a week after a slightly smaller one centered near Marysville last Monday. That quake registered as a 3.4 magnitude.
Mike Stickney, a geologist with the Montana Bureau of Mines & Geology, said that it’s unlikely the two events were related.
Stickney explained, “They’re separated from each other by a number of miles, and probably just coincidence that they happened a week apart.”
Helena sits in a seismically active belt across the middle of Montana, so earthquakes aren’t unusual across the region.
Most notably, Helena was devastated by two magnitude-six quakes in 1935.
“Those two earthquakes together damaged more than 60 percent of the buildings in Helena, caused four deaths, and then over the following six months there were more than 1,800 earthquakes that were big enough to be felt in Helena.”
Geologists say there’s no reason to expect further quakes, but people in this area should be paying attention.
“We have no reason to believe that these are leading up to anything more significant. Both earthquakes serve as a reminder that we do live in earthquake country, and that precautions are always a good idea.”
State geologists say there have been a number of aftershocks since the most recent earthquake, but they were too small for most people to notice.