We are not talking about the massive quake that jolted China on Monday. It's the worst-case temblor imagined for Utah.

Bob Carey, the state government's top earthquake planner, says China's tragedy can also serve as a reminder for Utahns to be ready for the Big One.

"There is a lot of comfort in knowing you are prepared for the event," he said. "That's half the battle."

Geologists and emergency planners estimate a magnitude-7 earthquake would affect about 80 percent of Utahns in 11 counties that include the populous Wasatch Front.

A quake that magnitude would kill between 5,100 and 6,200, depending on the time of day it strikes, Carey said. Damages to buildings would be about $42 billion.

In light of the projected hazards, the Utah Seismic Safety Commission plans a survey of state-owned buildings that are un-reinforced masonry. It also plans a priority list of school buildings thought to be at greatest risk to severe ground-shaking.

"In Utah, we are very well in tune with where we need to be," Carey said, pointing to up-to-date building codes, "and we are well on the way to getting there." Utah's emergency preparedness information is available at beready.utah.gov.

- Judy Fahys