DOES DEGREE OF CREVASSING INFLUENCE SUPRAGLACIAL LANDSLIDE RUNOUT?

Landslides are a common geological hazard in steep sloped regions around the world. They are particularly prevalent in glacial and periglacial landscapes, where a combination of oversteepening, loss of buttressing from thinning ice and climatic changes may all contribute to slope destabilization and collapse. The potential runout distance of landslides is important to determine, as it determines the area affected by collapses. The roughness of the surface over which landslides flow is known affect their mobility and flow parameters, however has not been studied in detail in collapses emplaced onto ice. Here I compare and contrast two recent landslide deposits emplaced onto the Southern Patagonian Icefield, and evaluate the influence of ice surface smoothness on the characteristics of the deposit. Secondly, I use a numerical granular flow model to simulate known landslides, and evaluate i) whether degree of crevassing of the glacier surface influences landslide runout distance or flow path, and ii) whether smoothing of crevasses by lower resolution elevation models may lead to over or underestimation of supraglacial landslide hazard. This will in turn feed into hazard models of the many rapidly deglaciating regions around the world.