USGS digs trench on Teton range mountain to study fault line

Researchers came to Teton Village hoping to study the Teton fault line. They weren’t exaclty sure where it might be at first, but the landscape gave some clues.

“The Teton fault extends across the landscape,” Chris DuRoss, USGS Research Geologist, said. “It’s a steep slope. That is evidence of large earthquakes that have occurred here, where everything on the valley side has dropped down relative to the mountains.”

Before they can study the fault line, researcher first have to dig a large trench. It will be 10 feet deep.

“Right now the backhoe is on top of what we call a fault scarp, or a scar from earthquakes,” DuRoss said. “And so the backhoe’s gonna work its way down slope for another maybe 75 feet. And so it will continue down across that steep slope and be about 20 feet wide.”

But digging the trench won’t come without difficulties.

“The main challenge is that we could run into a lot of large rocks,” Bill Schreiber, Jackson Hole Mountain Resort Engineer, said. “We’ve been digging on the mountain for quite a number of years. Very often in this area of the mountain, we can run into boulders that are anywhere from three feet to six feet to 10 feet in diameter.”

Scientists are interested in learning more about earthquakes in the area. Research in the 90s found large magnitude earthquakes can occur here. And they are now hoping to expand their knowledge of the fault line.

“What we’re hoping to find here is a history of earthquakes over the past, say, 10,000 years,” DuRoss said. “We’re really interested in how many earthquakes have occurred in that period and how large they were. And that information together gets used to estimate the hazard from this fault.”

Researchers will be working on the fault line for about two weeks. They said it could take anywhere from a couple months to half a year to study their findings before publishing them.