1934 – Hansel Valley, UT – M 6.6

Intermountain Seismic Belt Historical Earthquake Project

March 12, 1934 – Hansel Valley, UT – M 6.6

Believed to be the most severe earthquake in Utah’s recorded history, the 1934 Hansel Valley earthquake was reportedly felt as far west as Elko, Nevada and as far east as Rawlins, Wyoming. Felt reports were also issued from as far north as Boise, Idaho and as far south as Richfield, Utah.

The main shock occurred approximately 30 miles north of the Great Salt Lake at 8:05 a.m. local time. Five significant aftershocks were recorded over a nearly eight-week period from March 12 to May 6, 1934.

Some of the most severe damage was reported in Logan, Utah and surrounding communities. At least two public buildings in the area had to be abandoned. A three-story brick building on the campus of the Utah State Agricultural College was, reportedly, split from top to bottom. In Preston, Idaho, the shaking dislodged a 150-pound capstone from the top of the local high school building, separating the west wall from the rest of the building.

Other reports of damage included falling chimneys, broken windows, cracked walls and falling plaster. Swinging light fixtures were observed during the earthquake. Furniture rocked back and forth or rolled across floors. Dishes and goods fell from shelves and clocks stopped. Near the epicenter, in Snowville, Utah, the water main was broken and out of service for 10 hours. In some locations schools were evacuated and closed, particularly following the first aftershock.

Near the epicenter of the earthquake the appearance of several fissures or cracks in the ground surface were observed. Witnesses reported hearing loud roars as the fissures ruptured. A geologist who later examined the area reported one of the fissures to be about eight miles in length. He found a maximum fissure width of 14 inches, with a maximum drop of the ground on one side measuring 19 inches. Other reports noted a downward displacement of the ground on the east of the larger, predominantly north-south trending fissures.

Phenomena described as sand or mud cones were observed near the epicenter. There were also sightings of new springs and streams changing course. Artesian wells that had been long dry began flowing with water. Other wells, active prior to the earthquake, ceased to flow for several hours.

In many locations, shaking from the earthquake sent people running out of doors. There were also reports of people fainting from fright. In areas of intense shaking, people were unable to stand during the earthquake.

Two deaths were attributed to the earthquake. Ida Atkinson died instantly from a heart attack upon hearing that the shaking she felt was due to an earthquake. Salt Lake City waterworks employee Charles Bithel was injured when a six-foot trench in which he was working at the time of the earthquake caved in. Bithel died from his injuries the following day in a local hospital.


For additional information about this earthquake:

Earthquake Summary 3D Newspaper Articles 3D Photos 3D Blank Thumbnail
Personal Accounts 3D Additional Resources 3D Blank Thumbnail Blank Thumbnail

For more information about this project:

ISB Hist EQ Proj


1959 – Kanab, UT – M 5.7

Intermountain Seismic Belt Historical Earthquake Project

July 21, 1959 – Kanab, UT – M 5.7

This earthquake was felt over an area of 21,000 square kilometers, primarily in southern Utah and northern Arizona, according to newspaper accounts. Dishes and canned goods were knocked to the floor, cars were jostled on roads, and minor rockslides occurred. Felt reports were received from as far south as Flagstaff, Arizona–approximately 195 miles from the epicenter.

Near the epicenter, in the Kanab-Fredonia area, there were also reports of windows and dishes breaking, as well as canned goods tumbling from market shelves. In Kanab, the police chief reported bricks falling from at least one chimney. And plaster in the county courthouse was shaken from the walls. A truck driver traveling through the area at the time of the earthquake related that he “thought his steering had gone haywire.”

The earthquake, which occurred at 10:39 am local time, sent frightened Kanab residents scurrying from their homes–but no injuries or significant damage was reported.


For additional information about this earthquake:

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

For more information about this project:

ISB Hist EQ Proj


UUSS and University of Utah Seismology at AGU 2016

AGU Fall Meeting 2016 (American Geophysical Union) presentations from UUSS and other University of Utah Seismologists.

Amir Allam

Jamie Farrell

Paul Geimer

Keith Koper

Guanning Pang

Kevin Ward

Sin-Mei Wu

Hao Zhang


Origins of a National Seismic System in the United States

Origins of a National Seismic System in the United States

John R. Filson, Walter J. Arabasz


This historical review traces the origins of the current national seismic system in the United States, a cooperative effort that unifies national, regional, and local-scale seismic monitoring within the structure of the Advanced National Seismic System (ANSS). The review covers (1) the history and technological evolution of U.S. seismic networks leading up to the 1990s, (2) factors that made the 1960s and 1970s a watershed period for national attention to seismology, earthquake hazards, and seismic monitoring, (3) genesis of the vision of a national seismic system during 1980–1983, (4) obstacles and breakthroughs during 1984–1989, (5) consensus building and convergence during 1990–1992, and finally (6) the twostep realization of a national system during 1993–2000. Particular importance is placed on developments during the period between 1980 and 1993 that culminated in the adoption of a charter for the Council of the National Seismic System (CNSS)—the foundation for the later ANSS. Central to this story is how many individuals worked together toward a common goal of a more rational and sustainable approach to national earthquake monitoring in the United States. The review ends with the emergence of ANSS during 1999 and 2000 and its statutory authorization by Congress in November 2000.

1915 – Provo, UT – M 5.0

Intermountain Seismic Belt Historical Earthquake Project

July 15, 1915 – Provo, UT – M 5.0


According to newspaper accounts this earthquake was felt throughout the Utah, Salt Lake, and Bear River Valleys, and also in Provo Canyon, Tooele, Parley’s Canyon, and Park City, Utah.  The felt area measured 13,000 square kilometers.

In parts of Utah Valley buildings swayed, chimneys toppled, building walls were cracked, and individuals were knocked from chairs and couches. Wallpaper was split over doors and plaster was cracked and shaken loose. Dishes and pans rattled. In Provo Canyon shaking from the earthquake caused rockslides which blocked at least one road. At Utah Lake an upheaval of water, like a small tidal wave, was sighted.

In the Salt Lake Valley clocks stopped, windows and dishes rattled, and furniture was knocked over. Cans and packages were shaken from grocery store shelves.

Shaking appeared to be more pronounced in the upper floors of taller buildings both in Provo and Salt Lake City. In some locations both in the Utah and Salt Lake Valleys, the shaking caused individuals to rush out of buildings. This was the case throughout Provo where people hurried into the streets wondering what had happened. It was reported that more than an hour passed before the city resumed normal activities.

There were no reports of injuries or significant damage from the earthquake.


For additional information about this earthquake:

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

For more information about this project:

ISB Hist EQ Proj


1975 – Yellowstone National Park, WY – M 6.1

Intermountain Seismic Belt Historical Earthquake Project

June 30, 1975 – Yellowstone National Park, WY – M 6.1

This earthquake was located approximately 5 miles ESE of Norris Junction, in Yellowstone National Park. According to newspaper accounts, no casualties resulted from the earthquake and damage was minor. Near the epicenter, telephone service was temporarily knocked out. The earthquake also dislodged boulders that temporarily blocked a road between Norris and Madison Junction – however, campgrounds and park facilities remained open.

A park service employee reported, “There wasn’t any noise; no dishes rattled. There was just a gentle rolling of the floor.”

The earthquake shook buildings and rattled windows 200 miles away from the epicenter, and was reported felt both in Great Falls and Billings, Montana. The total felt area of the earthquake was 50,000 square kilometers.

A significant aftershock (magnitude 5.5) occurred just over 17 months later on December 8, 1976, approximately 5 miles W of Norris Junction. This earthquake was the largest since the June 30, 1975 main shock, and was felt over an area of 5,000 square kilometers.

Park officials noted that the aftershock shook buildings, but no damage was reported. One park official believed that damage to the terrain would likely be limited to rockslides. The earthquake occurred after the close of the summer tourist season – the park service received no inquiries about the earthquake from individuals inside park boundaries.


For additional information about this earthquake:

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

For more information about this project:

ISB Hist EQ Proj


A uniform moment magnitude earthquake catalog and background seismicity rates for the Wasatch Front and surrounding Utah region: Appendix E in Working Group on Utah Earthquake Probabilities (WGUEP)

Arabasz, W.J., Pechmann, J.C., and Burlacu, R., 2016, A uniform moment magnitude earthquake catalog and background seismicity rates for the Wasatch Front and surrounding Utah region: Appendix E in Working Group on Utah Earthquake Probabilities (WGUEP), 2016, Earthquake probabilities for the Wasatch Front region in Utah, Idaho, and Wyoming: Utah Geological Survey Miscellaneous Publication 16-3, variously paginated.

This appendix to the report by the Working Group on Utah Earthquake Probabilities (2016) describes full details of the construction and analysis of a refined earthquake catalog and the calculation of seismicity rates for the Wasatch Front and surrounding Utah region. The earthquake catalog covers the period from 1850 through September 2012. The catalog region extends from lat. 36.75° to 42.50° N and from 108.75° to 114.25° W. A uniform moment magnitude, M (and quantified magnitude uncertainty), is determined for each earthquake in the catalog.

Electronic Supplements (.xlsx)

E-1.  Best-Estimate Moment Magnitude (BEM) Earthquake Catalog

E-2.  Moment Magnitude Data

E-3.  Merged Subcatalog A, Jan. 1850-June 1962

E-4.  Merged Subcatalog B, July 1962-Dec. 1986

E-5.  Merged Subcatalog C, Jan. 1987-Sept. 2012

E-6.  Worksheets for Mobs, M~, Mpred (I0)

E-7.  Worksheets for Xnon, Xmix (Subcatalogs A, B)

E-8.  Worksheets for Xvar, Xi (Subcatalog B)

E-9.  Worksheets for Xvar, Xi (Subcatalog C)

E-10.  N* Counts for the WGUEP and Utah Regions

Earthquake Probabilities for the Wasatch Front region in Utah, Idaho, and Wyoming

Wong, I., W. Lund, C. DuRoss, P. Thomas, W. Arabasz, A. Crone, M. Hylland, N. Luco, S. Olig, J. Pechmann, S. Personius, M. Petersen, D. Schwartz, R. Smith, and S. Bowman (2016). Earthquake Probabilities for the Wasatch Front region in Utah, Idaho, and Wyoming, Utah Geological Survey Miscellaneous Publication 16-3,  418 pp.

UUSS 2015 Annual Report

UUSS Annual Report 2015

2015 Annual Report

2015 has been another vibrant and productive year for the University of Utah Seismograph Stations (UUSS). Our longstanding partnership with the United States Geological Survey (USGS) was extended with a new, 5-yr cooperative agreement from the USGS Earthquake Hazards Program. This award ensures that earthquake monitoring in Utah will continue to operate with state-of-the-art equipment and software at least through 2020. Congratulations to the UUSS staff for all their hard work on the USGS proposal, it was truly a team effort.

The legacy of UUSS in earthquake monitoring and research was recognized in 2015 as two former UUSS Directors received prestigious awards for career accomplishments. Research Professor Emeritus Dr. Walter J. Arabasz received the 2015 Alfred E. Alquist Special Recognition Medal from the Earthquake Engineering Research Institute, while Professor Emeritus Dr. Robert B. Smith received the 2015 Paul G. Silver Award from the American Geophysical Union. Congratulations to Walter and Bob for the leadership and service they have provided to the seismological community over the last several decades.

UUSS developed a new monitoring capability in 2015 with the acquisition of nearly 50 new wireless seismographs. The instruments were purchased in collaboration with Dr. Fan-Chi Lin and other University of Utah geoscientists, and will allow for the imaging of shallow Earth structure at a very small scale as well as the detection of small aftershocks that follow regional earthquakes. Please look inside to read about one of the first experiments carried out with the new instruments.

We expect great new things in 2016 as well. Keep an eye out for an updated UUSS web page and expanded social media presence. We also look forward to a celebration of the 50th anniversary of UUSS, in April 2016.

Magnitude 4.0 east of Jackson, WY

us10004t1f_ciimOn February 26, 2016, an earthquake of magnitude 4.0 struck about 31 km (19 miles) east of Jackson, WY at about 5:00 PM local time.  The quake was reported felt by over 150 people in the Teton region.  There were no reports of any damage.  The earthquake occurred in the Gros Ventre range east of Grand Teton National Park near the location of previous seismic activity.  In 2010 there was a swarm of earthquakes, including a M4.8 earthquake, ~11 km (7 miles) north of this event.Fig04.1_seis_map


The Teton region is part of the Intermountain Seismic Belt, a region of relatively high seismicity in the Intermountain West that extends from northern Arizona to western Montana.  Most of the seismicity in the Teton region occurs east of Grand Teton National Park in the Gros Ventre range while there is very little earthquake activity on the Teton Fault.





News accounts for this event can be found at the following links:

Jackson Hole News & Guide, February 26, 2016

Casper Star Tribune, February 26, 2016

Jackson Hole News & Guide, February 27, 2016