Geologists Prepare For ‘The Big One’

Eastern Idaho and western Wyoming are known for their majestic mountains, but below them is a disaster waiting to happen.

To see what Teton County officials are doing to better prepare the valley for earthquakes, we joined up with geologists from the University of Idaho who are discovering where the danger looms.

Beneath the beauty of the Tetons sit a number of fault lines; if one of them moves, it would shake every part of the valley differently.

To see where the greatest threat lies, geologists like Bill Phillips are gathering data to find out what areas would shake the most in the event of an earthquake.

As Phillips and his colleagues with the Idaho Geological Survey strike a giant mallet on a metal plate, it sends a seismic pulse into the earth.

The sensors then measure the strength and speed of those vibrations.

By hitting the strike plate a number of times, they can collect the average of the seismic velocity at the measurement site.

The measurements will better help county officials understand what areas pose a greater risk to tremors.

The biggest threat, however, lies along the 36-mile-long Teton Fault.

“It hasn’t been active historically, but there is good geological evidence indicating it is dangerous fault and it could produce an earthquake of magnitude 7,? Phillips said.

A magnitude 7 is a large earthquake, but only a fraction the size of the earthquake that devastated Japan.

“We can’t have the sort of earthquakes they had in Japan: it’s not in the cards for our geology, fortunately,? Phillips said.

And knowing what could come will better prepare those who live there.

“Engineers and architects, if we give them this information, they can do a lot to build structures to avoid earthquake damage,? Phillips said.

County Emergency Coordinator Greg Adams said the new data could even help improve county building codes.

“Basically what we will do with this information is some good earthquake modeling to pinpoint where we need to do some more mitigation work and focus our efforts on the spots that really matter,? Adams said.

Geologists will be in the field for the rest of the week and hope to measure about 25 locations around the valley.