Computer simulation of rock-glacier development under viscous and pseudoplastic flow

The rock-glacier debris transport system is mathematically linked to its bedrock-cliff source area by combining expressions for debris input and rock-glacier flow with a continuity equation. Numerical solutions are achieved by computer simulation, given the initial conditions of a 295-m cliff and a 10-m basal talus. Resulting system configurations depend upon rockwall weathering rate and rock-glacier flow resistance, as well as the type (viscous or pseudoplastic) of rock-glacier deformation. Steady-state equilibrium is achieved more quickly under pseudoplastic flow, but for given rates of rockwall retreat and flow resistance, steady-state rock glaciers tend to be larger and more powerful under viscous flow. When rock-glacier development is simulated under the assumption of cyclic climatic fluctuation, resulting geometries are similar for viscous and pseudoplastic flow. However, the rock-glacier output response to debris input is shown to be less lagged and less amplified under pseudoplastic flow.