A cautionary note for rock avalanche field investigation: Recent sequential and overlapping landslides in british columbia

Abstract

Large rock avalanches on glaciers are an annual occurrence in the mountains of western North America. Following an event, landslide investigators may strive to quickly arrive on site to assess the deposit. Satellite remote sensing imagery demonstrates that caution is warranted for on-site field assessments. We combine Landsat, Sentinel-1 (radar), Sentinel-2, and Planet imagery to reconstruct the events of four recent overlapping rock avalanche deposits in British Columbia. In our examples, substantial rock avalanches are closely followed (days–months) and buried by much larger landslides. We suggest that landslide investigators exercise caution when assessing fresh rock avalanche deposits in the field.