Rockfall, Cliff Retreat in Yosemite Valley since Last Glacial Maximum

The granitic cliffs of Yosemite Valley produce frequent rockfalls, modifying the landscape but also posing risk to park visitors. Analyses of terrestrial lidar and historical structure-from-motion photogrammetry data provide relatively precise short-term (approximately 40 years) rates of rockfall and cliff retreat. Those same data can also be used to estimate long-term (postglacial) rates through analysis of talus accumulation. Comparison of short- and long-term rates reveals complex spatial and temporal patterns of rockfall and provides a broader context for evaluating modern hazard conditions.

Stock G (2021) Pace of rockfalls and cliff retreat in Yosemite Valley since the Last Glacial Maximum. USGS Landslide Hazards Program Seminar Series, 27 October 2021.