Modeling degradation of terrace scarps in Grand Teton National Park, USA

The widely used linear diffusion model for hillslope evolution does not accurately predict the degradation of terrace scarps produced by the Late Pinedale West Spalding Bay Channelway (WSBC) near Jenny Lake in Grand Teton National Park, Wyoming USA. These scarps, cut into identical cohesionless quartzite gravel, were formed nearly simultaneously, during the brief period of time the WSBC was active. They are assumed to have had the same initial morphology as scarps currently forming along Snake River that are cut in the same material: a straight midsection sloping at 30° and a horizontal base and crest. The model best able to fit the observed morphology and the change in morphology with scarp height specifies the downslope debris flux is proportional to slope gradient raised to a power of 3.4.