Decameter thick remnant glacial ice deposits on Mars

Susan Conway (1) , Matthew Balme (2)

1 LPG - Laboratoire de Planétologie et Géodynamique [UMR 6112]
2 School of Physical Sciences [Milton Keynes]

On Mars, 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 30 m 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 4 km 3 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.

Domains: Planetology; Glaciology; Geomorphology

Susan Conway, Matthew Balme. Decameter thick remnant glacial ice deposits on Mars. Geophysical Research Letters, 2014, 41 (15), pp.5402-5409. ⟨10.1002/2014GL060314⟩. ⟨insu-02276025⟩