Debris Flow on a Seasonally Frozen Rupture Surface at Moose Lake, British Columbia

In early month of November 2007, a 1.4 km debris flow initiated on a steep south-facing slope above Moose Lake in Mount Robson Provincial Park, British Columbia. Snow meltwater was likely concentrated along a shallow seasonally frozen rupture surface, generating high pore water pressure. The debris flow bifurcated into two concentrated gullies before distributing as a debris flood on a snow-covered fan. The debris flow crossed a twin pipeline corridor and came to rest in a ditch against a highway berm. There was no damage to infrastructure. In many ways, the landslide resembles skin flows described in permafrost zones.