Earthquake tally near Bluffdale keeps rising; 139 in 12 days

(Rick Egan | The Salt Lake Tribune) Paul Roberson points out a map of the Seismograph Stations, at the Frederick Albert Sutton Building, home to the Department of Geology and Geophysics at the University of Utah. Wednesday, Feb. 20, 2019.

There’s been a whole lotta shakin’ goin’ on in Bluffdale — literally. According to the University of Utah Seismograph Stations, the area experienced 139 earthquakes from Feb. 13 through Monday.

The largest earthquake in the area — the “mainshock” — occurred at 5:09 a.m. on Feb 15, registering a 3.7. According to the stations, 13 quakes occurred before that; the largest was a 3.2 foreshock that came 7 minutes before the main shock.

Of the 125 aftershocks, the largest — a 3.1 magnitude, struck Saturday at 2:31 a.m. It was one of six aftershocks of magnitude 2.0 or higher. No injuries and no significant damage have been reported from any of the quakes.

According to seismologist James Pechmann at UUSS, while small quakes do not necessarily portend the big one is about to strike, they also don’t act as a “safety valve” to “relieve pressure” and lessen the chances of a much larger earthquake.

According the UUSS, there are small earthquakes in Utah every day, “although most of them are too small or too far from population centers to be felt.” And, while it’s “possible” that the Bluffdale quakes are occurring on the Wasatch Fault, “it is also possible that they are occurring on a minor, unnamed fault.”

UUSS did warn that the Bluffdale area quakes “serve as a reminder that Utah is earthquake country and a large, damaging earthquake could occur at any time. Therefore, everyone living in Utah should strive to be prepared for large earthquakes.”