Decameter thick remnant glacial ice deposits on Mars
نویسندگان
چکیده
OnMars, a smooth, draping unit—the “latitude-dependant mantle” (LDM), believed to comprise meter thick layers of dust and ice—extends from the midlatitudes to the poles, covering at least 23% of the surface. We show that the LDM can be 30m deep on pole-facing crater walls, and by measuring the erosional and depositional volumes of small gullies that incise these LDM deposits, we show that it must contain between 46% and 95% ice by volume. Extrapolating to a global scale, these deposits account for ~10 km of near-surface ice, doubling previous LDM volume estimates. Thick LDM deposits can be emplaced during the many orbital variation-driven climate excursions that occurred during the Amazonian period. We suggest that LDM deposits are similar to ice sheets composed of massive ice with a surface lag.
منابع مشابه
Sequestered glacial ice contribution to the global Martian water budget: Geometric constraints on the volume of remnant, midlatitude debriscovered glaciers
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