LIDAR MAPPING OF LANDSLIDES AND SECONDARY FAULT SCARPS, TETON RANGE, WYOMING

Bare earth LiDAR data (<1 m resolution) were analyzed to refine mapping of the primary scarp of the Teton fault, Wyoming, and to map previously unidentified landslides and secondary fault scarps along the east side of the Teton Range. The Tetons, a prominent north-south mountain range in western Wyoming, are bounded on the east by the Teton fault, an active normal fault that has potential to rupture in a magnitude 7 or higher earthquake. The fault poses a significant ground rupture and shaking hazard to Teton National Park and the greater Yellowstone area.

Though the primary fault is well known, many landslides and secondary scarps have not been recognized or mapped because they are not visible on the ground, satellite images, or aerial photographs. However, through the application of standard GIS analysis tools (e.g., hillshade, slope, aspect, and contour), they were identified, enhanced, and digitally mapped on bare-earth LiDAR data. Low sun-angle lighting perpendicular to the mountain front and linear and histogram stretches of the primary and derived data enhanced the landslides and secondary scarps. The proximity of multiple landslides to the fault suggests a high probability for coseismic landslides, which pose a significant risk to Teton National Park visitors. Detailed mapping of the fault and landslides may allow mitigation of these hazards.