PRESS RELEASE University of Utah Seismograph Stations Released: September 24, 2019 11:00 AM MDT
The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.9 occurred at 10:15 AM on September 24, 2019(MDT). The epicenter of the shock was located north of the Great Salt Lake, 14 miles northwest of Tremonton, UT.
This earthquake was reported felt throughout northern Utah including in the city of Tremonton and the surrounding communities. A total of 45 earthquakes of magnitude 3.0 or greater have occurred within 16 miles of the epicenter of this event since 1962. The largest of these events was a magnitude 4.5 on July 05, 1989, 11 miles west-southwest of Tremonton, UT.
Anyone who felt the earthquake is encouraged to fill out a survey form on the US Geological Survey website: earthquake.usgs.gov.
Date (UTC): September 24, 2019 Time (UTC): 16:15 Date (local): September 24, 2019 Time (local): 10:15 AM MDT Latitude: 41 48.94′ N Longitude: 112 23.38′ W Preferred magnitude: 3.90 Ml
In the Fall of 2015 and 2016, The University of Utah, in collaboration with the National Park Service and the University of Texas at El Paso installed dense seismic arrays centered on Old Faithful Geyser in Yellowstone National Park. The goals of this project are to image the shallow velocity structure beneath and around Old Faithful in order to identify areas of shallow, active hydrothermal activity as well as to learn more about these hydrothermal systems, in particular Old Faithful. The Upper Geyser Basin (Figure 1), where Old Faithful is located, has one of the highest concentrations of hydrothermal features in the world.
In November of 2015, 133 seismometers were deployed for 2 weeks (Figure 2) collecting continuous passive seismic data. The average station spacing was ~50 meters and the aperture of the entire array was ~1 km.
In November of 2016, in order to achieve a higher station density, a different approach was taken in that smaller dense arrays with ~20 meter spacing were deployed for 24-48 hours and then were moved to different locations around Old Faithful for another 24-48 hours until the area of interest was covered (Figure 3). In addition, while each individual array was in, we did active seismic sources using a sledgehammer throughout the array. A subset of instruments was deployed in the same location throughout the experiment in order to tie all the individual sub-arrays together.
Data are being analyzed to image the shallow subsurface beneath the Upper Geyser Basin near Old Faithful.
Intermountain Seismic Belt Historical Earthquake Project
June 12, 1930 – Grover, WY – M 5.8
In the early hours of Thursday, June 12, 1930, a magnitude 5.8 earthquake occurred in Grover, Wyoming—approximately 10 miles north of Afton, Wyoming.
The shock was widely felt in the community of Grover. Loud noise accompanied the earthquake. Cracking occurred in a building and a swimming pool in the community. Cracks in plaster were also reported (Neumann & Bodle, 1932)
The earthquake was felt in Star Valley, Wyoming, where residents were awakened when their houses began shaking.