Collaborative Research: Landslides related to the 2015 Mw 7.8 Gorkha earthquake, from ground motion and hazard to geomorphic response

University Of Southern California, Los Angeles CA

Investigators

Abstract

Landslides triggered by large earthquakes pose immediate and prolonged hazards. At the same time, these events record valuable scientific information about energy release during earthquakes, which in turn promotes erosion of the Earth's surface. Despite decades of research on this topic, the rarity of large earthquakes means that there is little data by which to evaluate key concepts. The April 25th magnitude 7.8 earthquake in Nepal offers the opportunity to study a region where the earthquake history is well known and seismic risk is high. Results from this project will evaluate patterns of seismic energy release not predicted by ground motion simulations and roles of rock weathering on long-term slope stability and landslide risk. Such data is essential for improving prediction of landslides related to earthquakes worldwide. A multi-disciplinary research team will couple geotechnical approaches to slope stability with geochemical studies of the slope debris. The proposed research will include seismic geophysical techniques to characterize the subsurface and an application of unmanned aerial vehicles (UAVs, or drones) to characterize the material properties of the rocks that failed in landslides. The intent is to apply cutting edge characterization techniques that were previously unavailable for any past major earthquake event. Geochemistry data from the slope deposits and river sediment will be used to place these geotechnical data within a broader context of weathering and erosion models.