Earthquake database for Utah Geological Survey Map 277: Utah earthquakes (1850–2016) and Quaternary faults: Utah Geological Survey Open-File Report 667

The Utah Geological Survey (UGS), University of Utah Seismograph Stations (UUSS), and Utah Division of Emergency Management (UDEM) recently published the Utah Earthquakes (1850–2016) and Quaternary Fault Map (UGS Map 277). The new map shows earthquakes within and surrounding Utah from 1850 to 2016, and faults considered to be sources of large earthquakes.

Utah Earthquakes (1850-2016) and Quaternary Faults

 

The faults shown on the map are considered geologically active, have been sources of large earthquakes (about magnitude 6.5 and greater) during the Quaternary Period (past 2.6 million years), and are the most likely sources of large earthquakes in the future. Most of the small to moderate-sized earthquakes on the map are “background” earthquakes not readily associated with known faults and too small to have triggered surface faulting (under about magnitude 6.5).

 

There is a 57% probability (over 1 in 2 chance) that a magnitude 6.0 or greater earthquake will occur in the Wasatch Front region in the next 50 years. To address this threat, the Utah Earthquake Program, consisting of the UGS, UUSS, and the UDEM, developed the map so the public could more fully understand the hazard from earthquakes and faults, as well as the resulting risk to property, infrastructure, and life safety in Utah. Users of the map will be able to determine past earthquake locations and relative magnitudes (size), along with the locations of active faults and the timing of their most recent movement.

 

Printed copies of the map are available for $15 at the Utah Department of Natural Resources Map & Bookstore. The map is also available as a PDF download at https://ugspub.nr.utah.gov/publications/maps/m-277.pdf (44 by 62 inches in size) and can be printed on a wide-format printer.

The database for the seismicity plotted on the map, together with explanatory information, is provided in a companion report:
Arabasz, W. J., Burlacu, R., and Pechmann, J. C., 2017, Earthquake database for Utah Geological Survey Map 277: Utah earthquakes (1850–2016) and Quaternary faults: Utah Geological Survey Open-File Report 667, 12 p. plus 4 electronic supplements, available as a PDF download.
The electronic supplements include the data for the seismic events plotted on the map, which are listed in two separate catalogs, each in the form of a Microsoft Excel workbook and an ArcGIS feature class within a file geodatabase. The catalog files are available for download.

1988 – San Rafael Swell, UT – M 5.3

Intermountain Seismic Belt Historical Earthquake Project

August 14, 1988 – San Rafael Swell, UT – M 5.3

This earthquake was located approximately 10 miles ESE of Castle Dale, Utah in Emery County.

There were no reports of injuries or serious damage resulting from the earthquake. Reports indicate that the earthquake was felt as far east as Golden, Colorado, as far south as Albuquerque, New Mexico, as far west as Delta, Utah, and as far north as Brigham City, Utah. The earthquake was reportedly felt particularly in valleys, while less noticed in mountain areas.

Minor damage in Emery County consisted of cracks in foundations, chimneys, and old buildings. Dishes and store goods fell from shelves and pictures were dislodged from wall hooks. Cracks and plaster damage were also observed in ceilings and walls.

Calls about the earthquake were received from several coal mines in the area, but there were no reports of injury or damage. Local dams were examined and found to be sound.

Rock falls were a notable feature of this earthquake. Fallen boulders impeded travel on some roadways. In many locations, falling rocks sent up clouds of dust that were visible for many miles.

Near the epicenter, north of Ferron, Utah a resident reported seeing dust clouds on the western ridge that partially obscured Ferron Mountain and the cliffs around the Wilberg Mine. “You couldn’t see the mountain up around Wilberg for five to 10 minutes because of the dust. Same on the desert [to the east]. Just a big string of dust from as far south to as far north as you could see.”

 

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

 

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

 

1915 – Provo, UT – M 5.0

Intermountain Seismic Belt Historical Earthquake Project

July 15, 1915 – Provo, UT – M 5.0

map-july15_1915

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