A large rockslide-debris avalanche in cohesive soil at Pink Mountain, northeastern British Columbia, Canada

In early July 2002, a large rockslide-debris avalanche occurred on the west slope of the Pink Mountain anticline in northeastern British Columbia (57 degrees 04'N; 122 degrees 52'W). The slopes have been subjected to previous deformation and landsliding. Pre- and post-slide digital elevation models (DEMs) were created from aerial photography. Approximately 1.04 M m(3) of sandstone and shale travelled nearly 2 km from an elevation of 1460 m to 10 10 m. The landslide has a fahrboschung of 11.6 degrees and covered 43 ha. The rock debris entrained a certain amount of fine-textured till and colluvium increasing its volume by 15%. This entrainment caused partial liquefaction of the underlying soil thereby enhancing the mobility of the landslide. We used a Bingham theological model to dynamically model the landslide with excellent correspondence between the analysis of the actual observed behaviour of the landslide. (c) 2005 Elsevier B.V. All rights reserved.