Science of the Magnitude 5.7 Magna, Utah earthquake (March 18, 2020)_UTD GEONEWS

I’m here to tell you about the science behind the Wednesday March 18 earthquake that happened near Magna, Utah, not far from Salt Lake City. The earthquake struck a little after 8 in the morning and was magnitude 5.7. The earthquake was strong enough to shake up residents, knock out power, and damage some buildings but fortunately no one was killed or injured. This was a moderate earthquake. What else do we know about the Magna earthquake? We know that the main fault movement occurred about 12 kilometers or about 8 miles deep in the crust on a steep fault that trends NNW. This was what geologists call normal faulting, which happens in regions where Earth’s crust is being stretched by tectonic forces. Faulting to make the Magna earthquake happened along the Wasatch fault, which can be followed for 390 kilometers or 240 miles in northern Utah. The Wasatch fault marks an important tectonic boundary between the high Wasatch Mountains to the east and the Great Salt Lake to the west. Millions of years of movement along the Wasatch fault is responsible for the spectacular scenery of this region. Because the fertile farmland lies just west of the Wasatch Fault and the water source lies in the mountains to the east, the region around the fault is where the Mormon pioneers settled in the mid-1800’s. This is also where most of the people of Utah live, including its largest city, Salt Lak City. Normal faulting along the Wasatch fault marks the easternmost limit of what geologists call the Basin and Range Province. This is a broad region of crustal stretching that has completely changed the landscape of western Utah, Nevada, and eastern Oregon over the past 25 million years or so. Earthquakes can be expected where the Earth is stretching and that includes the Basin and Range Province. Stretching today is concentrated on the eastern and western margins of the Basin and Range Province. The Ridgecrest, California earthquakes of July 2019 announced that the western margin of the Basin and Range was still stretching and sliding and the March 2020 Magna, Utah earthquake answered that the eastern margin was too. We hope you enjoyed our story; check out other videos including UTD Geonews at our website of YouTube channel, both called “UTD Geoscience Studios”.