A newly-discovered seismic fault line in central Idaho could produce a 7.5-magnitude earthquake, according to scientists at Idaho State University.
The 40-mile-long fault line beneath the northern Rockies had not been mapped before and could unleash a quake "in the next few decades," according to one of the scientists, who spoke to Reuters.
"If it does happen it will be a rather large earthquake," Glenn Thackray, chairman of the school's geosciences department, told Reuters.
The most vulnerable town is Stanley, with a population of only 100, but a 7.5-magnitude quake would likely cause serious damage and be felt in Boise, 80 miles away.
"Scientists located the fault with a remote sensing technique that relies on laser-equipped airplanes. They were able to gather data about its history by analyzing sediment cores lifted from Redfish Lake, a mountain lake on the fault line famous for its historic sockeye salmon runs," Reuters reported.
Major seismic events took place on the fault line 7,000 and 4,000 years ago, Thackray said, meaning that another event is statistically "due," but such activity is unpredictable.
He said Stanley should improve its building codes and emergency preparedness plans in light of the findings.