Sulphur Peak Earthquake Information

On September 02, 2017, in eastern ​Idaho ​near ​the ​town of ​Soda Springs a magnitude 5.3 earthquake occurred that was widely felt throughout southeastern Idaho and northern Utah.  This earthquake has been followed by a very active aftershock sequence. These earthquakes are slightly outside of the University of Utah Seismograph Stations area of responsibility, but the area is of interest to UUSS and the USGS Earthquake Hazards Program.

UUSS in partnership with USGS have deployed two UUSS 3-channel strong-motion systems and six USGS 6-channel seismic systems (broadband and strong-motion) within 50 km of the seismicity.

The following page includes information about the earthquake sequence and webicorders for the temporary stations.  We will update the page with more information over time.

Magnitude 3.4 earthquake near Monroe, UT

PRESS RELEASE

University of Utah Seismograph Stations

Released: September 24, 2017 1:00 PM MDT

The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.4 occurred at 10:38 PM on Saturday,
September 23, 2017 (MDT), in southern Utah. The shock was located beneath the Sevier Plateau, 6 km ( 4 mi) east-southeast of the town
of Monroe, UT, and 18 km (11 mi) south of the town of Richfield, UT. The earthquake was reported felt in the towns of Monroe, Richfield,
and Joseph, Utah. It was followed by two small aftershocks, one of M 1.7 at 10:46 pm on Saturday night and the other of M 1.6 at 09:43
on Sunday morning.

Yesterday evening’s earthquake occurred within a seismically active area of Utah A total of 23 earthquakes of magnitude 3.0 or greater
have occurred within 25 km (16 mi) of the epicenter of this event since 1962. The largest of these events was a magnitude 5.2 on
October 04, 1967, 10.1km ( 6.3 mi) ESE of Sevier, UT.

Anyone who felt the earthquake is encouraged to fill out a survey form either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): September 24, 2017 Time (UTC): 04:38

Date (local): September 23, 2017 Time (local): 10:38 PM MDT

Latitude: 38 36.39′ N

Longitude: 112 3.43′ W

Preferred magnitude: 3.4 Ml

Magnitude 3.3 near Park City, UT

PRESS RELEASE

University of Utah Seismograph Stations

Released: September 18, 2017 12:00 PM MDT

The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.3 occurred at 11:21 AM on September 18, 2017 (MDT). The shock was located 14 km (8 miles) beneath the Wasatch Mountains, 5 km (3 miles) south of the town of Summit Park, Utah, and 11 km ( 7 mi) WNW of Park City, UT. This earthquake was reported felt in Park City and Salt Lake City, Utah, other locations in the Salt Lake Valley, and in northern Utah County. Four other earthquakes of magnitude 3.0 or greater have occurred within 25 km (16 miles) of the epicenter of this event since 1962. The largest of these events was a magnitude 3.6 on June 30, 1999, 6.9km ( 4.3 mi) W of Park City, UT.

Anyone who felt the earthquake is encouraged to fill out a survey form either on the Seismograph Stations website: www.quake.utah.edu or the US Geological Survey website: earthquake.usgs.gov.

 

Earthquake Summary:

Date (UTC): September 18, 2017 Time (UTC): 17:21

Date (local): September 18, 2017 Time (local): 11:21 AM MDT

Latitude: 40 42.05′ N

Longitude: 111 36.55′ W

Depth: 11.0 km below sea level
13.6 km below the surface

Preferred magnitude: 3.30 Ml

Magnitude 5.3 near Soda Springs, ID

Press Release

University of Utah Seismograph Stations

Released: September 02, 2017 8:00 PM MDT

The University of Utah Seismograph Stations reports that a moderate
earthquake of magnitude 5.3 occurred at 05:57 PM on September 02, 2017
(MDT), as computed by the USGS. The epicenter of the shock was located
11 mi E of Soda Springs, ID. This event was preceded by a magnitude 4.3
foreshock and followed by numerous aftershocks, including seven with
magnitudes between 3.2 and 4.1 (all USGS magnitudes).
The 5.3 mainshock was reported felt in Idaho, Wyoming, and also across
northern Utah in the cities of Logan, Bringham City, Ogden, Salt Lake City,
Draper, and Provo.

Since 1962, a total of 87 earthquakes of magnitude 3.0 or greater have
occurred within 16 mi of the epicenter of today’s magnitude 5.3 event.
The largest of these events was a magnitude 4.7 on October 13, 1982,
9 mi NNW of Georgetown, ID.

Anyone who felt the earthquake is encouraged to fill out a survey form
either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary (USGS parameters):

Date (UTC): September 02, 2017 Time (UTC): 23:57

Date (local): September 02, 2017 Time (local): 05:57 PM MDT

Latitude: 42 37.44′ N

Longitude: 111 23.46′ W

Preferred magnitude: 5.3 Mw

UUSS 2016 Annual Report

cover page of 2016 annual report2016 Annual Report

In April of 2016 the University of Utah Seismograph Stations (UUSS) celebrated the 50th anniversary of its creation as an organizational unit within the University of Utah. We celebrated this milestone with a party honoring the founding director, Dr. Ken Cook, and the unveiling of a new historical display just outside the Rio Tinto Earthquake Information Center. The ceremony was well attended by current and former UUSS employees, colleagues in the College of Mines and Earth Sciences, representatives of sister agencies in the Utah Earthquake Program, members of Dr. Cook’s family, and many other friends of UUSS. Here’s to another 50 years of reducing the risk from earthquakes in Utah through research, education, and public service.

2016 was also a year of transition for UUSS. Our administrative manager, Martha Knowlton, retired after 14 years of service. We will miss Martha’s attention to detail, professionalism, and strong work ethic. UUSS communications specialist Sheryl Peterson, who has worked in various capacities for UUSS since 1989, also left in the fall of 2016. Sheryl’s competence, cheerfulness, and organizational skills will serve her well as she pursues a new career as director of advancement operations at Southern Virginia University. We will also miss Katherine Whidden, a research scientist, student mentor, and the UUSS public information officer, who left in 2016 (ending a five-year stint with UUSS) to travel the country in an RV with her husband, John. In other news, Cindi Meier, who worked at UUSS during 1994-1999, agreed to return as our new full-time administrative officer. In 2016, we also welcomed Dr. Hao Zhang to UUSS as a post-doctoral research scientist focusing on the detection and location of sequences of very small earthquakes.

We look forward to an exciting new year in 2017. 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 nd out about the latest seismic activity in Utah. You can also follow UUSS on Twitter with the handle @UUSS_Quake_Info.

Ongoing Yellowstone Earthquake Swarm North of West Yellowstone, MT.

August 03, 2017 UPDATE: The University of Utah Seismograph Stations (UUSS) is monitoring an earthquake swarm which is currently active on the western edge of Yellowstone National Park.  The swarm began on June 12th, 2017 and, as of 13:00 MDT on August 2nd, 2017, is composed of 1,562 events with the largest magnitude of ML 4.4 (MW 4.4) (Figure 1).  The swarm consists of one earthquake in the magnitude 4 range, 8 earthquakes in the magnitude 3 range, 134 earthquakes in the magnitude 2 range, 505 earthquakes in the magnitude 1 range, 879 earthquakes in the magnitude 0 range, and 35 earthquakes with magnitudes of less than zero.  These events have depths from ~0.0 km to ~14.0 km, relative to sea level.  At the time of this report, there were 125 felt reports for the M4.4 event that occurred on June 16, 2017 at 00:48:46.94 UTC (June 15, 2017 at 18:48:46.94 MDT).  The M4.4 event has an oblique strike-slip moment tensor solution (Figures 1 & 2).  In addition, four other earthquakes in the swarm have been reported felt.

 

 

Figure 1. Location of the earthquakes that are part of the swarm as of August 3, 2017 at 01:00 PM MDT (red symbols).

 

Figure 2. Moment Tensor solution for the M4.4 event showing the fit between data (black) and synthetics (red dashed).

Moment Tensor for M 4.5

Figure 3. Animation of the June 2017 Yellowstone earthquake swarm.  Earthquakes appear as red circles as they happen, then transition to blue.  After they have occurred, they appear as black circles.  The size of the circles are proportional to the earthquakes magnitude.

Earthquake swarms are common in Yellowstone and, on average, comprise about 50% of the total seismicity in the Yellowstone region.

UUSS will continue to monitor this swarm and will provide updates as necessary.

 

If you think you felt an earthquake, please fill out a felt report at: http://earthquake.usgs.gov/earthquakes/dyfi/.

Yellowstone swarm continues with M 3.6 felt near West Yellowstone, MT

Released: July 18, 2017 03:15 PM MDT

The University of Utah Seismograph Stations reports that a minor
earthquake of magnitude 3.6 occurred at 02:31 PM on July 18, 2017
(MDT). The epicenter of the shock was located 9.3 mi N of W.
Yellowstone, MT. This earthquake is part of an ongoing sequence
of earthquakes that began on June 12, 2017 and included a
a magnitude 4.4 event on June 15, 2017, 9.0 mi NNE of W.
Yellowstone, MT. Today’s M 3.6 earthquake was reported felt in
Yellowstone National Park and in West Yellowstone, MT. It was
followed by numerous smaller earthquakes, the largest of which
had magnitudes of 2.8 and 2.9. The total number of located
earthquakes in the current sequence has now exceeded 1200.

Anyone who felt the earthquake is encouraged to fill out a survey form
either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): July 18, 2017 Time (UTC): 20:31

Date (local): July 18, 2017 Time (local): 02:31 PM MDT

Latitude: 44 47.25′ N

Longitude: 111 2.27′ W

Preferred magnitude: 3.60 Ml

1928 – Helena, MT – M 5½ ±

Intermountain Seismic Belt Historical Earthquake Project

February 29, 1928 – Helena, MT – M 5½ ±

The 1928 Helena, Montana earthquake had no reported injuries or damage. The shaking startled people throughout the city of Helena and was more noticeable on upper floors of buildings with two or more stories above ground. The shaking was severe enough to disrupt a trial in one city courthouse. Without taking time to formally adjourn the proceedings, the judge and others fled the courtroom as the shaking began.

The earthquake was reported felt in areas southeast of Helena including: Trident, Three Forks, Manhattan, Logan, Lombard, and Sixteen-Mile Canyon. White Sulphur Springs, to the east of Helena, also reported earthquake shaking.

There were reports of shaken buildings, windows rattling, furniture moving, and goods being shaken from shelves.

 

For additional information about this earthquake:

Earthquake Summary 3D Newspaper Articles 3D Blank Thumbnail Blank Thumbnail

For more information about this project:

ISB Hist EQ Proj

 

Magnitude 3.4 Arizona earthquake near St. George, UT

PRESS RELEASE

University of Utah Seismograph Stations 

Released: July 12, 2017 09:10 AM MDT

The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.4 occurred at 08:41 AM on July 12, 2017 (MDT).  The epicenter of the shock was located nine miles SSE of St. George, UT.  A total of 6 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 5.9 on September 02, 1992, two miles SSE of Washington, UT.

Today’s earthquake was reported felt in Saint George, UT and surrounding cities.

Anyone who felt the earthquake is encouraged to fill out a survey form either on the Seismograph Stations website: www.quake.utah.edu or the US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC):   July 12, 2017         Time (UTC):   14:41

Date (local): July 12, 2017           Time (local): 08:41 AM MDT

Latitude:     36º 58.79′ N

Longitude:    113º 33.96′ W

Preferred magnitude: 3.40 Ml