Wasatch Fault Scenario Report

Utah Chapter of EERI Completes Earthquake Scenario Report 

The EERI Utah Chapter, in cooperation with FEMA, has completed an earthquake scenario report for the greater Wasatch Front region.  A publication of this detail has never been created for Utah. The Utah Chapter hopes that the report will “catalyze public and private actions that will increase pre-disaster resiliency through earthquake preparedness – being prepared to withstand, to respond and to recover.”  The report will be presented by the Chapter to the Utah Seismic Safety Commission (USSC) at their quarterly meeting at the end of July.

The report uses results developed by the Utah Division of Emergency Management from their ongoing work with the HAZUS loss-estimation software.  The scenario is for a magnitude 7.0 earthquake on the Salt Lake City segment of the Wasatch fault. 

Estimated aggregated losses, for the 12 most northern Utah counties, illustrate the severity of this event.  The human impact of the report focuses on the HAZUS results in terms of deaths, injuries, and sheltering needs. The HAZUS results also emphasize the huge economic impact showing the loss from structural, nonstructural (i.e. walls, ceilings, cladding, and HVAC), building contents, and inventory damage in addition to the cost of lost wages, lost rental income, and relocation.  The reports lists the estimated lifeline losses and also provides time estimates for recovery for selected utilities.  In addition, the report presents estimates on the number of building inspectors that will be needed to perform building safety evaluations, and it estimates the amount of debris generated that must be hauled away.

The scenario report concludes with a call to action, providing nine recommendations to the USSC. These recommendations provide the Commission with a direction forward that includes consensus building of stakeholders, advocates for pre-disaster planning and mitigation, and encourages the ongoing study of geologic hazards along with the continued monitoring of seismic activity, and finishes with the need for disaster resiliency planning.

The Chapter would like to thank the Scenario Subcommittee for their volunteered time and hard work on the report.  Subcommittee members include Kris Pankow, Chair, Barry Welliver, Walter Arabasz, Pete McDonough, Josh Groeneveld, Leslie Youd, Gary Christenson, Steve Bowman, Sheryl Peterson, Brent Maxfield, and Bob Carey.

After presentation to the USSC, a hard copy of the report will be mailed to jurisdictions along the Wasatch Front.  

To join our effort or find out more, contact: utah@eeri.org

What is an Earthquake Scenario?

Earthquake scenarios provide opportunities to examine alternative futures and stimulate creative thinking about the need for new policies and programs. Incorporating the latest scientific, engineering and societal knowledge about a region’s seismic hazard, local soil characteristics, building types, lifelines, and population characteristics, a scenario can create a compelling picture that members of the local community can recognize and relate to. Not only can such a scenario stimulate new policies and programs, the process of scenario development itself often results in greater understanding and improved trust and communication between members of the scientific, engineering, emergency management, and policy communities resulting in a “new community” dedicated to seismic risk reduction. Some reasons for conducting an earthquake scenario include:

  • It affords the opportunity for a community, organization or group to come together, get buy-in for the issues and discuss problems and potential solutions associated with a future earthquake.
  • It is an effective way to make sure everyone participating in the process is talking about and visualizing the same issues.
  • When used as part of an emergency response or management exercise, it can identify weaknesses and highlight strengths in a response or management system, allowing for modifications before a real disaster.
  • It can serve as an advocacy tool to build community commitment to the earthquake risk reduction, as well as to secure funding and resources for solutions to the hazards laid out in the scenario.
  • It is a useful tool for providing a picture of alternative outlooks in a community, with and without risk reduction actions.
  • It can be used effectively as the basis of exercises and trainings in a community or organization, helping to answer the questions of “what if”, which are necessary to an exercise.
  • It is a useful tool for testing a community’s ability to respond, and for training community and organizational leaders to better respond to a large seismic event.