Publication Date:
2011-04-21
Description:
Sublimation at the ice-substrate interface with pressure build-up is an accepted mechanism for the production of fan deposits on the southern polar CO2 ice cap on Mars. Fluid dynamics modeling has been used to investigate gas outflow through vents in a CO2 slab ice. Small (5–25 m in length) fan deposits seen on the annual southern CO2 ice cap can be produced by a steady-state in which open vents continuously outgas in response to sub-surface sublimation generated by diurnal energy input through translucent impermeable (to gas) ice slabs. This would produce diurnally-controlled deposits which would change orientation with time in response to winds thereby explaining observations made by HiRISE on MRO. Gas flow below the ice can reach up to 25 m/s close to the vent. Dust flow in the sub-ice cavity has also been computed but velocities are much lower with the main acceleration occurring
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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