Modeling the development of martian sublimation thermokarst landforms

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Sublimation-thermokarst landforms result from collapse of the surface when ice is lost from the subsurface. On Mars, scalloped landforms with scales of decameters to kilometers are observed in the mid-latitudes and considered likely thermokarst features. We describe a landscape evolution model that couples diffusive mass movement and subsurface ice loss due to sublimation. Over periods of tens of thousands of Mars years under conditions similar to the present, the model produces scallop-like features similar to those on the Martian surface, starting from much smaller initial disturbances. The model also indicates crater expansion when impacts occur in surfaces underlain by excess ice to some depth, with morphologies similar to observed landforms on the Martian northern plains. In order to produce these landforms by sublimation, substantial quantities of excess ice are required, at least comparable to the vertical extent of the landform, and such ice must remain in adjacent terrain to support the non-deflated surface. We suggest that Martian thermokarst features are consistent with formation by sublimation, without melting, and that significant thicknesses of very clean excess ice (up to many tens of meters, the depth of some scalloped depressions) are locally present in the Martian mid-latitudes. Climate conditions leading to melting at significant depth are not required.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling the development of martian sublimation thermokarst landforms
Series title Icarus
DOI 10.1016/j.icarus.2015.07.033
Volume 262
Year Published 2015
Language English
Publisher Elsevier
Contributing office(s) Astrogeology Science Center
Description 16 p.
First page 154
Last page 169
Other Geospatial Mars
Online Only (Y/N) N
Additional Online Files (Y/N) N
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