Just after 7:00 a.m. on March 18, 2020, an earthquake with a magnitude of 5.7 on the Richter Scale hit the Salt Lake area about 4 miles from Magna, UT. The quake cut power to about 55,000 residents, says utility company Rocky Mountain Power. It is the largest earthquake to hit Utah since 1992. At least six aftershocks had been recorded within 20 minutes of the initial earthquake. Several large media sources have reported on the earthquake, including NBC, CNN, USAToday, and CBSNews.
The tremor has had a large influence on broader sectors of life as well. The Salt Lake City International Airport was forced to divert incoming flights to give time for inspections of the runway to take place. The airport has closed roads into the airport, telling people not to come. Additionally, KUTV news anchor Brian Mullahy said that the earthquake means no flights in or out of the airport for several hours. The public transportation systems in Salt Lake City have come to a halt, and all TRAX cars have found a station safely and evacuated passengers.
Another large worry with the earthquake is the potential for infrastructure damage. In terms of the Richter Scale, levels 0 to 3 generally aren’t felt by people, levels 3 to 5 are felt clearly, and anything above 5.1 has the potential to cause damage to infrastructure. Salt Lake City Mayor Erin Mendenhall said, in reference to infrastructure damage, “The City is assessing the situation now and I’ll circle back with an update when I have it. Be safe.”. The Utah Department of Transportation had inspection crews out immediately and said in a tweet, “So far there doesn’t appear to be any, but we’re checking everything out, specifically our bridges,”.
Perhaps the largest worry after an earthquake is the question, “could there be another one?”. There have been small aftershocks, but because of the close proximity to the Wasatch fault line, a large earthquake could be enough to trigger the massive earthquake that seismologists have been predicting for decades. The United States Geological Survey, aided by the University of Utah Seismology Department, forecast that there will likely be more aftershocks in the coming days. Within one week, the USGS predicts that there is about a 90% chance that there will be anywhere from one to 220 earthquakes larger than 3.0 in the coming week. They further predict that there is a 17% chance that there are one to three earthquakes measuring at 5.0 or higher in the next week. A seismologist from the University of Utah predicts a 5% chance that in the next week, an earthquake measuring higher than 5.7 will occur.
While the likelihood of there being another big earthquake is fairly low, less than a one in five chance, it is important to be prepared. The USGS urges people to be ready in the case of a larger quake, and to remember to drop, cover, and hold on.