‘The Big One,’ Raises Concerns for Kennecott

We often talk about “the big one,” hitting the Beehive State.  But now we’re learning it it happens it could mean trouble for Kennecott’s facility on the south slope.


Seismologists See Salt Lake City Future Disaster by Reading the Dirt

If you missed it a couple of weeks ago, here is an article outlining the paleoseismic study some of our UGS geologists helped with on a trench.

Not far from I-215 in Salt Lake City, near the airport, a deep trench cuts through the earth. Though it looks like a sewer repair project, there’s nothing down here but dirt. And dirt, to the trained eye, can reveal quite a bit about a city’s future.


The Utah Seismic Safety Commission (USSC) has a new website!

The USSC is the central state organization for reducing Utah’s earthquake risk by coordinating efforts, developing public policy, and disseminating results. Here you can find a large earthquake Salt Lake City scenario, and helpful booklet “Putting Down Roots” on preparing for earthquakes. Use the search to find all other USSC documents including photographs and PDFs. Visit the website HERE to help make a plan with your family and friends!

Other helpful links:
Where to Find Earthquake Information
Putting Down Roots PDF

EERI Salt Lake City M7 Earthquake Scenario

A wonderful resource for earthquake safety and preparedness has just been released. The report was developed by the Utah Chapter of the Earthquake Engineering Research Institute (EERI) and was prepared for the Utah Seismic Safety Commission.

The Scenario for a Magnitude 7.0 Earthquake on the Wasatch Fault-Salt Lake City Segment: Hazards and Loss Estimates report provides information about the effects of the Wasatch fault scenario earthquake-in particular, how long it may take the state of Utah and its residents to fully recover and the potential long-term impacts on Utah’s economy. The ultimate goal of this report is to catalyze public and private actions that will increase pre-disaster resiliency through earthquake preparedness-being prepared to WITHSTAND, to RESPOND, and to RECOVER.

Follow this link to obtain a PDF copy HERE!

Compilation of 1970s Woodward-Lundgren & Associates Wasatch fault investigation reports and low-sun-angle aerial photography, Wasatch Front and Cache Valley, Utah and Idaho

OFR-632 insert

By: Steve D. Bowman, Adam I. Hiscock, and Corey D. Unger

This nine DVD set contains a descriptive 8-page report and digital files created from the Wasatch fault investigation project performed for the Utah Geologic and Mineralogical Survey (now the Utah Geological Suvey) and U.S. Geological Survey by Woodward-Lundgren & Associates. The project was performed to identify surface fault rupture hazard areas along the Wasatch fault in Cache Valley. This compilation contains digital scans of three separate Wasatch fault reports, 47 fault maps, and 1382 scanned low-sun-angle-arial photographs (frames). The digital files include aerial photograph scans in TIFF format, fault maps in TIFF and Adobe PDF formats, and index maps in Google Earth KMZ, GIS shapefile and Adobe PDF formats. Specialized software (not included) is required to utilized the Google Earth and GIS files, and can be downloaded from the internet.

This compilation will be useful for professionals involved with paleoseismology investigations; land-use planning and management; government agencies; and the general public and others as a historical archive. Low-sun-angle aerial photography was used to highlight certain topographic features, such as fault scarps and traces, for mapping purposes.


What Will Really Happen When San Andreas Unleashes the Big One?

Maybe some of you have seen the new movie “San Andreas.” So what could we expect to happen in the event of a giant earthquake on the San Andreas Fault? Read more in this article to find out.

A giant earthquake will strike California this summer. Skyscrapers will topple, the Hoover Dam will crumble and a massive tsunami will wash across the Golden Gate Bridge. Or at least, that’s the scenario that will play out on the big screen in San Andreas.


Like California, Utah is also earthquake country. One of the best forms of preparation is educating yourself and your family on what to do in the event of an earthquake. For more information on what you can do, see Putting Down Roots, or visit

How Big and How Frequent Are Earthquakes on the Wasatch Fault?

A team of scientists from the USGS Geological Hazards Science Center, led by Mendenhall Postdoctoral Fellow Scott Bennett and Research Geologists Ryan Gold, Richard Briggs, Christopher DuRoss, and Stephen Personius are collaborating with scientists at the Utah Geological Survey to gather data from new paleoseismic trenches along the Wasatch fault zone. These new datasets will help researchers to understand if past surface-rupturing earthquakes have spanned fault segment boundaries. They are also analyzing new high-resolution airborne LiDAR topographic data to characterize previously unmapped fault traces and to measure how vertical displacements (vertical offset of the ground surface from faulting) vary, both in space (from north to south) and time (the last 20,000 years).


Earthquake Risk in the Salt Lake Valley

In Christchurch, New Zealand in February, 2011, a magnitude 6.3 earthquake struck six miles from the city center. The sandy type of soil present in the area caused the ground to basically liquefy during shaking.

UGS Geologist Chris DuRoss is interviewed by KCPW: Explore Utah Science to discuss the hazard of liquefaction we face right here in the the Salt Lake Valley.


Earthquake Risk in the Salt Lake Valley

Michael Hylland, a geologist at the Utah Geological Survey, examines disruptions in the subsurface soil at a trench dug through a section of the Wasatch Fault



If highway construction projects have taught commuters anything, it’s that even a single lane restriction can bring traffic to a crawl. Now imagine the impact on your commute because of a unexpected force of nature — like a strong earthquake, a blizzard, flooding rains or a tornado.

Along Utah’s Wasatch front, a fault spans 240 miles, and 80 percent of Utah residents live along its path.

The Utah Geological Survey notes the fault “has the dubious distinction of being one of the longest and most active normal faults in the world.”

Other areas of the country are also near fault lines. And along the Wasatch fault, several dozen freeway overpasses cross the main corridors near which the fault travels.

Other areas are more prone to conditions that tornadoes form in. And others live in the paths of hurricanes. Still, blizzards, fires and other storms can prompt evacuations or paralyze an area.




Scientists have discovered evidence of four big earthquakes that rocked the Salt Lake Valley long before pioneers arrived — and they’re not on the well-known Wasatch Fault on the East Bench.

Geologists are getting their first good look at the West Valley Fault zone, just west of the Salt Lake International Airport. They’ve wanted to dig trenches in the area for years.

“We suspected that there had been numerous earthquakes in this region,” said Chris DuRoss of the Utah Geological Survey.

The West Valley Fault zone is actually comprised of a dozen different fractures. They lie roughly between Redwood Road and 5600 West from about 1700 North to 4800 South. But since at least the 1980s the area on the margins of the Great Salt Lake has been too soggy to dig.

Over the last decade the shrinking lake receded several miles from the fault zone, and the water table has dropped. Now that the Utah Geological Survey has been able to dig three trenches, the water table is visible 10 feet below the surface.

Recently geologists had their first look underground, and it confirms their suspicions. The horizontal layers of sediment show clear signs of being broken by fault movements. It’s clear evidence of four big earthquakes in the last 15,000 years.