The strongest earthquake to hit the region in years as well as 140 smaller quakes occurred Saturday night to Wednesday night in Southeast Idaho, startling tens of thousands of residents.
Authorities said it does not appear that the quakes have caused any injuries to people or damage to structures (ADVICE ON WHAT TO DO IF AN EARTHQUAKE HITS YOUR TOWN IS AT THE END OF THIS ARTICLE).
The quakes have been felt in the Caribou County area, where all 141 occurred, as well as in cities in northern Utah and throughout Southeast Idaho. It's unknown when the earthquake swarm will end. Earthquake swarms have been known to continue for weeks or even months.
In recent decades Southeast Idaho has seen infrequent instances in which one to three weak earthquakes occur near the Western Wyoming border. Local authorities say they cannot ever remember any earthquake swarm in Southeast Idaho that comes even close to the current series of temblors shaking the region.
There were 25 quakes on Wednesday, 20 on Tuesday, 28 on Monday, 34 throughout the day on Sunday and 34 on Saturday night. All 141 of the quakes were reported by University of Utah Seismograph Stations.
Bannock County Sheriff Lorin Nielsen said he's been a law enforcement officer in Southeast Idaho for over 40 years and during that time there's never previously been so many earthquakes occurring in such a short time frame. He said at the most there have been up to three earthquakes that have occurred in short succession along the East Idaho-Western Wyoming border. The dozens of earthquakes that have occurred since Saturday night in Southeast Idaho are unprecedented, the sheriff said.
"I've never seen anything like this," Nielsen said. "My wife asked if we should leave the house."
The earthquakes occurred starting shortly before 6 p.m. Saturday. The second quake to strike was at 5:56 p.m. Saturday and it was the most powerful thus far. The quake was about 10 miles east of Soda Springs and registered at magnitude 5.3 — strong enough to possibly damage buildings. It's been years since Southeast Idaho has experienced a quake of over magnitude 5.0.
The earthquakes have occurred at various distances east, southeast and northeast of Soda Springs, Caribou County's largest city. The farthest away were about 20 miles southeast and northeast of Soda Springs and the closest was about 1 mile east of the city.
The quakes have been felt as far away as Salt Lake City, Logan and Ogden in northern Utah and Malad, Basalt, Arimo, Pocatello, Chubbuck, American Falls, Fort Hall, Aberdeen, Blackfoot and Springfield in Southeast Idaho.
Below is advice from the U.S. Department of Homeland Security via https://www.ready.gov/earthquakes on what to do if an earthquake hits your community:
Before An Earthquake
Before an earthquake occurs, secure items that could fall or move and cause injuries or damage (e.g., bookshelves, mirrors, light fixtures, televisions, computers, hot water heaters. Move beds away from windows and secure any hanging items over beds, couches, cribs or other places people sit or lie.
Practice how to “Drop, Cover, and Hold On!”
Plan and practice how to Drop to the ground, Cover your head and neck with your arms, and if a safer place is nearby that you can get to without exposing yourself to flying debris, crawl to it and Hold On to maintain cover.
To react quickly you must practice often. You may only have seconds to protect yourself in an earthquake.
Store critical supplies (e.g., water, medication) and documents.
Plan how you will communicate with family members, including multiple methods by making a family emergency communication plan.
- Consult a structural engineer to evaluate your home and ask about updates to strengthen areas that would be weak during an earthquake.When choosing your home or business to rent or buy, check if the building is earthquake resistant per local building codes.
During An Earthquake
If you are inside a building:
Drop down onto your hands and knees so the earthquake doesn’t knock you down. Drop to the ground (before the earthquake drops you!)
Cover your head and neck with your arms to protect yourself from falling debris.
If you are in danger from falling objects, and you can move safely, crawl for additional cover under a sturdy desk or table.
If no sturdy shelter is nearby, crawl away from windows, next to an interior wall.Stay away from glass, windows, outside doors and walls, and anything that could fall, such as light fixtures or furniture.
Hold on to any sturdy covering so you can move with it until the shaking stops.
Stay where you are until the shaking stops. Do not run outside. Do not get in a doorway as this does not provide protection from falling or flying objects, and you may not be able to remain standing.
If getting safely to the floor to take cover won’t be possible:
If getting safely to the floor will be difficult, actions before an earthquake to secure or remove items that can fall or become projectiles should be a priority to create spaces..
Identify an away from windows and objects that could fall on you. The Earthquake Country Alliance advises getting as low as possible to the floor. People who use wheelchairs or other mobility devices should lock their wheels, bend over, and remain seated until the shaking stops. Protect your head and neck with your arms, a pillow, a book, or whatever is available.
If you are in bed when you feel the shaking:
If you are in bed: Stay there and Cover your head and neck with a pillow. At night, hazards and debris are difficult to see and avoid; attempts to move in the dark result in more injuries than remaining in bed.
If you are outside when you feel the shaking:
If you are outdoors when the shaking starts, move away from buildings, streetlights, and utility wires. Once in the open, “Drop, Cover, and Hold On.” Stay there until the shaking stops.
If you are in a moving vehicle when you feel the shaking:
It is difficult to control a vehicle during the shaking. If you are in a moving vehicle, stop as quickly and safely as possible and stay in the vehicle. Avoid stopping near or under buildings, trees, overpasses, and utility wires. Proceed cautiously once the earthquake has stopped. Avoid roads, bridges, or ramps that the earthquake may have damaged.
After an Earthquake
When the shaking stops, look around. If the building is damaged and there is a clear path to safety, leave the building and go to an open space away from damaged areas.
If you are trapped, do not move about or kick up dust.
If you have a cell phone with you, use it to call or text for help.
Tap on a pipe or wall or use a whistle, if you have one, so that rescuers can locate you.
Once safe, monitor local news reports via battery operated radio, TV, social media, and cell phone text alerts for emergency information and instructions.
Check for injuries and provide assistance if you have training. Assist with rescues if you can do so safely.
If you are near the coast, learn about tsunamis in your area. If you are in an area that may have tsunamis, when the shaking stops, walk inland and to higher ground immediately. Monitor official reports for more information on the area’s tsunami evacuation plans.
Use extreme caution during post-disaster clean-up of buildings and around debris. Do not attempt to remove heavy debris by yourself. Wear protective clothing, including a long-sleeved shirt, long pants, work gloves, and sturdy, thick-soled shoes during clean-up.
Be prepared to “Drop, Cover, and Hold on” in the likely event of aftershocks.