Intermountain Seismic Belt Historical Earthquake Project
March 18, 2020 – Magna, UT – M 5.7
On Wednesday, March 18, 2020, Utah was jolted by a magnitude 5.7 earthquake that occurred 3.1 miles north of Magna, Utah. The shaking from the earthquake was widely felt throughout the Wasatch Front area of north-central Utah.
Interest from the public was high. In addition to the COVID-19 pandemic and the start of quarantine, this was the first moderate-sized earthquake many Utah residents experienced. Social media and other digital coverage made it a widely-covered event.
There were no serious injuries or deaths that were recorded. Several buildings sustained damages as a result of the earthquake. Magna’s main street and a nearby trailer park were the hardest hit areas. Most of the damage occurred on buildings with unreinforced masonry. Total damage estimates were around $48.5 million a month after the mainshock.
The M5.7 was the largest earthquake to occur in Utah since a magnitude 5.9 earthquake in 1992 in southwestern Utah near St. George. The earthquake occurred in a seismically active part of the Salt Lake Valley. Before March 18, the area experienced six magnitude 3.0 or larger earthquakes since 1962, the largest being the magnitude 5.2 on September 5, 1962.
The M5.7 was designated the mainshock of the Magna Earthquake Sequence. There were no foreshocks. Over the course of 2–3 months, the aftershocks grew to number over 2,000. This count included 6 earthquakes in the M4 range and 34 earthquakes in the M3 range.
The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.0 occurred at 02:56 PM on April 05, 2021 (MDT). The epicenter of the shock was located beneath Central Valley in south-central Utah, three miles south-southwest of the city of Richfield, Utah. This earthquake was reported felt in Richfield and in the nearby towns of Monroe and Salina. Today’s earthquake occurred within a seismically active area of Utah. Since 1962, 32 earthquakes of magnitude 3.0 or greater have occurred within 16 mi of the epicenter of today’s event. The largest of these events was a magnitude 5.2 on October 04, 1967, located 6.3 mi east-southeast of the town of Sevier, UT.
Anyone who felt the earthquake is encouraged to fill out a survey form on the US Geological Survey website: earthquake.usgs.gov.
2018 was an especially difficult year because of the unexpected death of Dave Drobeck on February 11. Dave served the University of Utah Seismograph Stations (UUSS) for over 20 years and was instrumental in developing the Yellowstone Seismic Network into one of the premier volcano monitoring networks in the world. Dave’s loss was especially hard on the UUSS engineering group—Corey Hatch, Wes O’keefe, and Jon Rusho—who had to take up extra work duties while grieving the loss of their colleague. A summary of Dave’s career was presented by Bob Smith at a ceremony on February 22, and is reprinted in this report.
While someone like Dave can never truly be replaced, I am happy to report that a former UUSS undergraduate research assistant, ArvindParapuzha, agreed to return to UUSS as a seismic engineer trainee in May, and that Wes O’keefe worked his first full field season in Yellowstone this past fall. On July 1, long-time seismic analyst Mark Hale was promoted to senior application systems analyst. Congratulations, Mark!
The biggest highlight of 2018 was the June 14 announcement that the University of Utah had been selected to receive a $140 million grant from the Department of Energy to develop the Frontier Observatory for Research in Geothermal Energy (FORGE) site near Milford, Utah. The selection was due in no small part to the effort of UUSS associate director Kris Pankow and her team of students and staff, who created a seismic mitigation plan for the project. Dr. Pankow will continue managing the FORGE seismic risk as work ramps up over the next several years.
We look forward to an exciting new year in 2019. I encourage you to visit our revamped web page at quake.utah.edu to stay up-to-date on our new initiatives and products as well as to find out about the latest seismic activity in Utah. You can also follow UUSS on Twitter with the handle @UUSSQuake.
UUSS Director Keith Koper sat down on Facebook live to explain how the UUSS responds to earthquake events, like the Magnitude 5.7 earthquake in Magna, UT. He also shared important things to know and simple steps to take to be prepared.