A Utah State University geophysics expert says there is little likelihood that Wednesday’s 5.7 magnitude earthquake along the Wasatch Front compromised any of the quake faults that cross Cache Valley, even though the temblor was felt strongly here.
The Wednesday quake, followed by scores of aftershocks, had an epicenter near Magna, just southwest of Salt Lake City along a branch of what is known as the Wasatch Fault System.
Cache Valley also has a variety of earthquake faults, but these probably weren’t affected by the jolt to the south and thus don’t pose any increased threat, according to James Bay, a USU professor of geotechnical engineering.
“Conventional wisdom says it’s very unlikely. It is believed the Wasatch faults and the other faults like the East Cache Fault and the Wellsville Fault are all segmented,” he told The Herald Journal. “When there is movement, it is pretty much constrained to one segment of the fault or maybe overlapping partly onto an adjacent segment. The likelihood of this causing anything in Cache Valley would be quite low.”
Bay pointed out the Wasatch Fault System poses as great if not greater risk to Cache Valley than the valley’s own earth fissures.
“The Collingston and Brigham City segments of the Wasatch Fault could produce a quite a bit larger earthquake than the East Cache Fault — the fault that’s pretty much underneath the university and most of the city of Logan,” Bay said.
The last major earthquake in Cache Valley occurred in 1962, when a 5.7 temblor centered near Richmond rocked the valley, causing widespread damage.
Wednesday’s 7:09 a.m. earthquake was felt by many Cache Valley residents — who described it as a back-and-forth rolling action that lasted about 30 seconds — but a lot of locals who were sleeping at the time say they missed the event. Others were jarred from sleep.
“I thought a much bigger dog than my dog jumped on the bed … no dog,” wrote one local on Facebook.
“Look, I am not an end times person, but holy s---, Cache Valley just had an earthquake,” wrote another resident on Twitter.
No significant damage was reported locally. The Cache County Sheriff’s Office issue a statement saying, “We have checked infrastructures and we can report we have found no damage at this time and everything appears normal.” And the cities of Logan and North Logan both reported critical infrastructure had been checked and deemed operable.
Utah Public Radio, quoting Logan City Councilwoman Amy Anderson, reported Logan took the preventative action of pulling all vehicles out of fire stations.
Anderson told UPR she woke up to text messages announcing the city had activated an emergency plan. “I texted with Mayor Daines and knew that when they felt the tremors she ordered all of the fire stations to pull all of their mobile vehicles out. I have already received several emails from planning and zoning just giving me confirmation that all of the buildings Logan City owns are all OK, that there has been no damage.”
State liquor stores have avoided a shutdown due to the coronavirus, but Wednesday’s earthquake resulted in several Utah state liquor store closures, including in Logan.
The Department of Alcoholic Beverage Control reported that several stores experienced broken bottles falling from shelves during the 5.7 magnitude quake. The agency said all stores in Wednesday’s earthquake zone would be closed the rest of the day Wednesday to check for structural damage and broken merchandise.
Meanwhile, in Rich County, the earthquake was reported to have a measurable effect on the waters of Bear Lake. The Twitter account of Bear Lake Watch, sponsored by the U.S. Geological Survey, posted a chart showing the lake level dipped and rose slightly (about .05 of a foot each way), after the earthquake.
“Not exactly a tsunami, but interesting,” the post said.