Though authorities aren't putting much stock in dire predictions of a substantial earthquake in December, they say if those predictions help make people prepare for the eventuality, so much the better.

Utah County lies adjacent to the Wasatch Fault, an active fault that hasn't experienced a large-magnitude earthquake (ranging between 7 to 7.5 on the Richter Scale) for almost 600 years. Most faults of the Wasatch's variety average 1,500 to 2,500 years between periods of large fault activity.However, that is only an average period - meaning there are periods of grouping in seismic activity and also slow periods - so the next big quake could hit at any time, "since there's no greater chance that it will happen in December than any other time," according to BYU civil engineering professor Les Youd.

Youd, who also spent 17 years with the U.S. Geological Survey, said that because of media attention being devoted to the quake predictions - from the same source that supposedly predicted last October's Bay Area quake - "there's been as much of an effect and preparedness action since perhaps the 1911 San Francisco earthquake. Maybe a bad prediction can do as much good as a good prediction."

A substantial portion of the preparedness action is coming from the Utah County Sheriff's Department, where Emergency Service Coordinator Dick Casto is contacting local governments to coordinate evacuation and relief plans throughout the county.

"It's not like we're unprepared for such an event," Casto said. "The prediction hasn't caused us to take more steps than we already have. Hopefully, the good that will come out of all this will be for the public to be more aware of what they need to do."

Casto said the county has had several studies done on the potential effects of such a disaster and has prepared a countywide master plan to coordinate services.

According to the studies, besides the quake and its immediate effects, the greatest single danger would be if Deer Creek Dam was damaged or burst. "There could be 2 1/2 feet of water in the Provo City center," Casto said.

Also, Youd said areas around Utah Lake, including Vineyard, Palmyra and Lake Shore, could receive substantial damage through liquefaction - in which loosely compacted soil particles can actually amplify the quake force or actually shift quite dramatically, as in a landslide. Both men agreed that under such circumstances, the most important thing is for people to not panic and to know proper protection procedures.

"The local and county governments would be in charge of bringing vital services back on line quickly, and other services will need to be provided by individuals or the community."

Both are lobbying for changes in state and local programs that will better prepare the state for such a disaster.

Youd and other members of the state's Earthquake Task Force have asked the Legislature to establish a seismic safety commission; to provide appropriations for more up-to-date seismic instrumentation; to make vulnerability assessments of bridges, fire stations and schools; and to make mandatory geologic hazard site investigations for critical government facilities.

Casto said the state is completing a laser monitoring system that will immediately notify local law enforcement and emergency agencies should the Deer Creek Dam fail. And Provo City is spending $45,000 on a siren system with a one-mile broadcast range to send out early warnings.

"We'll be doing all we can to have emergency services ready in such a scenario, but the rest will be up to families and individuals," Casto said.

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(Additional information)

In case of earthquake

Authorities suggest the following measures for families and individuals:

- Before: Practice protection procedures, including finding shelter; have food and water reserves, as well as first-aid supplies, for at least 72 hours; have portable radios, lamps and stoves available; secure gas-operated appliances, including stoves and gas heaters; be able to quickly, though temporarily, relocate.

- During: Immediately locate temporary shelter, such as crouching under a desk, doorway or in a corner, to protect against falling objects.

- After: Tend to minor injuries; locate all family members and move to a central point; check on neighbors and community.