Assessment of Martian Lake Hydrologic Index

Abstract Large lakes are sensitive to climate shifts. This study investigated an established terrestrial lake metric as a tool for differentiating climate regimes on Mars. A global survey of martian lake hydrologic index (HI), the ratio of lake area to drainage area, showed that most sites have intermediate values (0.30–0.65). This is a null result as such values do not meaningfully differentiate between warm-wet and cold-dry conditions. However, one regional cluster of extreme low H I values (<0.10) is identified, and is consistent with extreme aridity. This corridor along the equatorial dichotomy boundary in northern Terra Cimmeria formed during the Hesperian epoch or younger.