Salt Lake County's emergency-response plan is good, but liquefaction and ground displacement near the Wasatch Fault would likely cause significant damage in the event of a major earthquake, says a spokesman for the Federal Emergency Management Administration.
A FEMA field-research team is evaluating Salt Lake County's earthquake potential in advance of a special training course designed to help area officials respond to the major quake that FEMA Education Specialist Peter Vogel said will surely hit the Wasatch Front sometime.FEMA's earthquake predictions mirror those made by Utah geologists who study the Wasatch Fault. "It could go today, it could go next week, it could go next year, it could go in 1,000 years," Vogel said.
Using data provided by Salt Lake-area geologists and geological surveys, Vogel said the Wasatch Fault moves, on average, every 444 years. It's last significant movement was 1,700 years ago, he said.
Beginning Jan. 11, FEMA will fly about 60 officials from throughout Salt Lake County to the National Fire Academy in Emmitsburg, Md., where they will be trained how to respond to an earthquake simulation the FEMA team will prepare from information gathered in Salt Lake County this week.
FEMA has trained local officials in 75 similar classes since it began the training program in 1982.
Vogel wouldn't say how big the simulated earthquake would be or what damage will be spelled out in the scenario, but he promised the quake would be "substantial," and similar in magnitude to the earthquake that rocked San Francisco Oct. 17.
Liquefaction on soft soils caused the major damage in San Francisco's Marina District last week. Similar liquefaction is likely along the Jordan River corridor, Vogel said, which makes the chances good a quake would cause major damage to the I-15 freeway system and its many bridge structures. Major aqueducts that supply much of Salt Lake County's water traverse the Wasatch Fault numerous times, "Which just throws out the silly question: `What do you fight fires with?' "
It would not be unusual for dozens and even hundreds of fires to break out after a major earthquake, he said.
The first part of the earthquake school will deal with the initial response to a quake, resulting fires and mayhem likely to occur in the first 48 hours. Later segments of the four-day school will deal with the longer-term problems of rebuilding utilities and other elements of the infrastructure quickly and in a manner that would make them more resistant to a future earthquake.
The infrequency of the Wasatch Fault's movement complicates decisions planning officials make when determining what kind of building activity is appropriate in earthquake-prone areas. If the fault slips it's likely to be displaced 15 feet, Vogel said, but restricting construction because the area might experience an earthquake 300 years from now isn't reasonable.