Unique and Potentially Mars-Relevant Flow Regime and Water Sources at a High Andes-Atacama Site

Area of Science:

• Planetary Science
• Geology
• Hydrology

Background:

• The High Andes/Atacama Desert presents a hyperarid environment with rare snowfall.
• Subsurface ice and wind-transported grains play a role in preserving ephemeral water sources.

Purpose of the Study:

• To investigate flow-produced structures and unique flow regimes in the High Andes.
• To compare terrestrial hydrological processes with hypothesized Martian features like recurring slope lineae.

Main Methods:

• Field expedition to the High Andes/Atacama Desert region.
• Observation and analysis of erosional gullies and active infilled valleys.
• Identification of water (H2O) sources, including buried snow, surface snow, and residual ice.

Main Results:

• Two types of flow-produced structures (gullies and infilled valleys) were identified.
• Infilled valleys exhibited diurnal activity linked to subsurface water sources and percolation.
• Identified three H2O sources, including a novel source of residual ice from previous melting.

Conclusions:

• Terrestrial gullies and infilled valleys share similarities with Martian features, particularly recurring slope lineae.
• Diurnal activity in valleys is driven by insolation and subsurface snow movement, a process potentially active on Mars.
• The Ojos del Salado site provides a unique analogue for studying Martian hydrological processes in extreme environments.