ROCKFALL MONITORING IN THE NATIONAL PARKS

In National Park Service managed lands across the country, rockfall affects roads, trails, and other infrastructure related facilities. Rockfall is a recurrent and frequent hazard in areas of spectacular landscape and high relief. Rockfall risk reduction strategies in the National Park Service include quantitative risk estimation for specific rockfall hazards, monitoring of potential rockfall areas with vibrating wire crackmeters, exploring radar and thermal monitoring techniques, and an Unstable Slope Management Program. In areas where rockfall hazards with high potential consequences have been identified, rapid quantitative risk estimation techniques are helping managers put rockfall risk into a societal context. Rock fracture monitoring with vibrating wire crackmeters is shedding light on rockfall source areas and may help us better understand: triggering mechanisms, the extent of thermoelastic rock deformation, and potentially aid in identifying pre-failure warning signs. At Arches National Park, monitoring since 2015 shows significant thermoelastic deformation. At Grand Teton National Park, a large wintertime rockfall event was captured, allowing precursory deformation analysis. Instruments at Hawai‘i Volcanoes National Park capture brittle rock response to volcanic process and earthquakes and instruments at Zion and Chaco Canyons are monitoring potential rockfall source areas. Through these efforts, the National Park Service strives to reduce risk from rockfall hazards.