CACHE COUNTY, Utah (ABC4) — The new year is kicking off with a rumble in Cache County. Since New Year’s Day, more than one dozen earthquakes have hit the area, and one earthquake expert told ABC4 that this is called a “swarm” and is a gentle reminder that Utah has a lot of improvements to make to prepare for the “big one.”
According to the University of Utah Seismograph Stations, there have been 71 earthquakes within the Colorado Plateau since December 22, 2022. Of those, 14 occurred in Cache County within a three-day period with the largest occurring on Jan. 3.
“The earthquake I felt [on Jan. 3] was very short duration,” Brady Cox told ABC4. “So, it’s really just enough to get your attention.”
Within 24 hours, more than 400 people, including Cox, filled out a report to the United States Geological Survey stating he had felt the 3.2 magnitude earthquake that hit about six miles west of Logan.
Cox is a professor at Utah State University. He is also an earthquake engineer who’s traveled the world helping cities rebuild in the wake of large earthquakes for the last 30 years. He has traveled to many countries including Peru, Japan, New Zealand, and across the U.S.
He explained that this week’s quakes in Cache County were a swarm, and that they serve as a gentle reminder: “On an individual basis people need to be ready, but also on a state basis we need to be ready.”
Cox said the recent quakes in the county haven’t been big enough to really cause any damage. However, if there had been any kind of infrastructure directly over the sites where the quakes occurred, it would be a different story.
With so many earthquakes happening here Cache County over the last few days, some people may be wondering if there is any imminent danger or if a bigger earthquake may be coming soon. Cox explained that there really isn’t a perfect answer.
“We can’t say that we’re done, we can’t say that this is going to lead to anything else, we just don’t know,” he said. “We don’t know when, but the probabilities are high. We’re overdue for a large earthquake.”
Most of Utah’s population lives along the Wasatch Fault line and Cox said the line has a nearly 50% chance of a Magnitude 7 quake in the next 50 years.
The likelihood of this happening is something Cox believes that the state needs to pay attention to. Worldwide, he explained, one of the leading causes of earthquake deaths is unreinforced masonry structures — basically, brick and stone buildings that aren’t reinforced with steel. As many as 140,000 structures could meet that definition. That’s five times higher than unreinforced structures in CAlifornia, which has a higher population and a higher quake risk.
“We have a lot of people who are at risk in a large earthquake,” he stated. “In fact, there’s about 72,000 school children that attend a school that at least one of their school buildings on their campus is unreinforced masonry structure.”