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Carbon dioxide frost sublimation-induced flow model

Carbon dioxide frost sublimation-induced flow model
Carbon dioxide frost sublimation-induced flow model Illustration of a proposed sequence of events triggering a carbon dioxide-gas-fluidized flow. (A) Sunlight penetrates the semi-transparent carbon dioxide frost deposited on a slope, heating the underlying regolith. (B) The heating leads to an increase in temperature and pressure and the formation of carbon dioxide ice within the regolith. When the cryostatic pressure is reached, the carbon dioxide ice layer cracks and detaches from the underlying regolith. The pressurized carbon dioxide within the regolith is ejected, potentially carrying some regolith material with it. This violent depressurization leads to a quick sublimation of the carbon dioxide ice present in the pores, generating carbon dioxide gas. This destabilizes the regolith and generates viscous flows of material down the slope. (C) The ice-cemented soil at shallower depth becomes unstable and slowly loses its water ice through sublimation. (D) The local ice table deepens as the surface ice sublimates away. Repeating this process will create deep incision at gully location. From Pilorget and Forget (2016)