Earthquake fault identified in Idaho

The 40-mile fault at the base of the Sawtooth Mountains near the small town of Stanley was of some concern, and shaking from a temblor on the fault could extend to the state capital of Boise, Glenn Thackray, chairman of Idaho State University's geosciences department, said.

Scientists say they believe two earthquakes have occurred along the fault in the past 10,000 years, with one occurring 7,000 years ago and the other 4,000 years ago.

Discovering a fault of this size should not necessarily serve as an "alarm that something is imminent," John Ebel, a professor of geophysics at Boston College, said.

The Northern Rocky Mountain regions of Idaho, Wyoming and Western Montana are a seismically active zone and capable of producing some very large earthquakes, he said.

"Since we don't know when the next earthquake will occur, we simply need to prepare for it," Ebel told BBC News.

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