A quantitative evaluation of basal surface shapes to estimate bedrock landslide volumes

This talk will examine the use of logarithmic spirals and planar or bi-planar geometries to estimate failure surface shapes and volumes of previously documented bedrock landslides. We present an inventory of large rock slides and rock avalanches for which pre- and post-event topography data are available, examine failure surface shapes using post-event topographic data, and evaluate the suitability of different geometries for approximating bedrock landslide failure surfaces and volumes.