Constrain the processes driving present-day gully modification at Sisyphi Cavi

Establish which physical mechanism drives present-day gully modification at Sisyphi Cavi among competing processes involving CO2 ice, H2O ice, CO2-ice-driven fluidization, and avalanche-like granular flows.

Background

The paper evaluates several competing explanations for contemporary gully activity, including liquid-water or water-ice processes, CO2 geysers beneath translucent ice, CO2-ice fluidization, and avalanche or granular-flow mechanisms. The observations exclude neither every possible CO2-based process nor all combinations of ice and substrate effects.

The authors find no evidence for independently exposed H2O ice and identify a temporal mismatch between CO2 geyser indicators and gully modification. They therefore favor late-season CO2-ice-driven fluidization or avalanche processes, but do not claim that the mechanism has been definitively established.