ST. GEORGE — Southern Utah residents within a 30-mile radius reported feeling the effects of a 3.6 magnitude earthquake that struck Tuesday afternoon.
According to University of Utah seismograph stations that measured the temblor’s effect, the quake struck around 3:36 p.m. with an epicenter 5 miles east of Springdale.
The nearest measuring station – located in Kanab – estimated the depth of the earthquake to be about 12 miles underground, with a half-mile margin of error.
The U.S. Geological Survey confirmed the University of Utah’s report and began collecting “Did You Feel It?” reports from local residents that felt tremors. In just over an hour, the USGS received more than 60 responses from people in Kanab, Dammeron Valley, Hurricane and St. George.
Respondents used the Modified Mercali intensity scale to describe their perception of the shaking at their location. Most reported a second- or third-degree earthquake, which would be equivalent to the vibrations of a passing truck at most.
Britt Ballard, public information officer with the Springdale Police Department, said he didn’t personally feel the tremors and that police did not receive any reports of damage or injury.
As opposed to the perception-based Mercali scale, the seismic strength of an earthquake is measured in the logarithmic Richter scale – meaning each number increase is 10 times more powerful than the last.
A 3.6 magnitude earthquake like the one that occurred Tuesday is relatively minor, with hundreds of thousands of quakes that strong or weaker measured each year around the globe. According to the University of Utah, a total of eight earthquakes of magnitude 3.0 or greater have occurred within 16 miles of the epicenter since 1962.
Tuesday’s temblor was the strongest shake of those events. The next largest event was a magnitude 3.4 recorded on March 11, 1989, about 4 miles east of Colorado City.
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