New insights into rockfall triggering in Yosemite Valley
Greg Stock
Yosemite National Park
- Date & Time
- Location
- Online-only seminar via Microsoft Teams
- Host
- Steve DeLong
- Summary
Yosemite National Park contains some of the world’s most famous granitic landforms, characterized by near‑vertical cliffs that exceed 1 km in height. Frequent rockfalls from these cliffs are a dominant geomorphic process and present an ongoing hazard to the park’s approximately 5 million annual visitors. Building on prior USGS investigations, recent research has focused on quantifying how environmental forcing influences the stability of exfoliation sheets and contributes to rockfall initiation. Identified rockfall triggers range from high-magnitude, low frequency events such as seismic shaking to lower-magnitude but persistent mechanisms such as cyclical thermal stresses. This presentation will highlight new insights into rockfall triggering processes in Yosemite Valley, examine recent case studies, and outline current challenges and opportunities for improving rockfall hazard assessment and risk mitigation in one of the world’s most iconic landscapes.