Sub-ice lake scenario for Chaotic Terrains on Mars

Abstract

A 2D time-dependent thermo-mechanical model, including ice–water phase change and sedimentation process, is developed to study the effects of planetary heat loss and sedimentation rate on the time scale for melting and on the mechanical and hydrological stability of sub-ice lake scenario. The results show that planetary heat loss greater than 25 mW/m2 and sedimentation rates between 0.1 and 0.001 mm/yr are able to produce stable melting process, reaching a water thickness greater than 1.3 km. These parameters fully agree with the estimates obtained by geological and morphological observations. Afterwards, the water stored within the crater can be rapidly discharged toward the surface through fractures in the sediment cap. The consequent collapse would be 1.3–1.5 km, which agrees with the amount subsidence observed for Aram Chaos.