Geologists produce new Teton fault map for download
IDAHO FALLS, Idaho (AP) — A new fault map from the Wyoming State Geological Survey shows the Teton Range is still growing, with its fault line getting ever-so-slightly taller each year.
The Post Register in Idaho Falls, Idaho reports the map was created in an effort to study and track the fault line, and it’s now available for a free download on the Wyoming State Geological Survey website .
Geologists with state and federal agencies, academic organizations and consultants worked to create the map using a surveying method called light detection and ranging, or LIDAR. The method involves shooting light — in the form of a pulsed laser — at the ground from an aircraft to get a high-resolution, detailed image of the earth’s surface.
The map’s lead author, Mark Zellman with BGC Engineering, said the LIDAR equipment was able to capture greater detail than previous maps, which were limited by dense vegetation and rugged terrain.
“The new fault map represents a state-of-the-art understanding of the Teton fault’s length and location,” Zellman said.
The last major earthquake along the fault line occurred sometime between 4,500 and 8,000 years ago, Zellman said. The data shows that along the fault, the mountains are getting incrementally taller and the valley around Jackson Hole, Wyoming is dropping incrementally lower.
But the changes aren’t noticeable to the naked eye - they’re currently happening at a rate of about .8 millimeters each year. At that rate, it would take 300 years for the elevation to change by 1 foot (.3 meters).
Information from: Post Register, http://www.postregister.com