One of the fastest growing places in the U.S. is the Great Salt Lake Rift Valley of Utah. Geological studies clearly demonstrate a record of large earthquakes throughout the recent past in this region that occurred along various segments of the Wasatch Fault before it was settled.
Each fault segment has an earthquake recurrence interval of around 1200-1400 years. Some sections, like the Salt Lake City segment, have not experienced a major earthquake in over 1350 years. During that time enough energy has accumulated along the fault to cause a magnitude 7.0 earthquake.
Two million people live above the westward inclined fault in mostly unreinforced masonry buildings built before seismic codes were first enforced in the 1990’s. The majority of schools also fall into this category. Poorly supported critical services, such as gas and water pipelines, bridges and roads, and unstable slopes also pose a significant threat for emergency response to a major earthquake. Some of the steps that we have taken to help the citizens of Utah prepare have been:
- Present free workshops in various communities, informing people how to protect themselves from earthquake hazards, involving over 12,000 people
- Set up utahearthquake.org, a website that serves as a clearing house for information about how to prepare for an earthquake, and what to do during and after the event
- Advise state government and LDS Church leaders about seismic disaster risk reduction
- Persuade a major University to decommission its seismically vulnerable student dorms
- Assisted local communities along the Wasatch Front to pass a referendum to replace seismically vulnerable schools
Earthquake Safety Awareness Survey Results
In 2015, we conducted a major survey of people in Utah County to get a clearer understanding of public knowledge regarding earthquakes, earthquake safety and preparedness.
- 41% of the respondents were moderately, vaguely, or not at all aware that there is a significant threat of an earthquake
- 50% of the respondents feel slightly or not at all prepared for an earthquake
- 56% of the respondents guessed incorrectly about what to do if you are inside during an earthquake
- 64% of people would go to the internet to find out information on earthquake preparedness
FEMA Earthquake Simulation Results for Salt Lake City
The following statistics come from a simulation conducted by the Federal Emergency Management Agency.
- A 7.0 earthquake at 2 p.m., in the middle of the workday, would cause 100,000 injuries > 10,000 fatalities.
- Most injury and death caused by heavy damage of large numbers of unreinforced masonry buildings.
- Damage estimates of approximately 30 billion dollars in losses.
- More than 50% of Utah schools were built before seismic building codes, and many may collapse increasing the death toll among children