Experimental study of sediment transport processes by liquid water and brine under Martian pressure
Abstract
Martian slopes host downslope movement morphologies (including gullies and RSL) that have been observed to be active today. Some hypotheses about their formation and activity are related to water liquid flows. Few experiments have been performed to study how water transports sediments under Martian conditions, our work explore it further by realizing experiments of water and MgSO4-brine flows over sandy substrates at different temperatures (0-20°C) and at Martian pressure. Our main goal is to highlight the differences in terms of sediment transport between water and brine flows. On a cold sand (0-5°C) sediments are only transported through channels. At 0°C water starts freezing and seems to transport again more sediments than brine. On that cold sand water and brine channels are also morphologically different: water ones are short and wide when brine channels are long and thin. Consistent with the previous studies, over 15°C we observed transport processes related to boiling liquids with no terrestrial equivalent (grain ejection, pellets "levitation"...). At these temperatures water is less stable and so boils more and transports more sediments than brine. Extrapolated to Mars it means that water would be more efficient than brines to transport sediments on "hot" slopes.
- Publication:
-
EPSC-DPS Joint Meeting 2019
- Pub Date:
- September 2019
- Bibcode:
- 2019EPSC...13..576P