Effects of varying obliquity on Martian sublimation thermokarst landforms




Scalloped depressions in the Martian mid-latitudes are likely formed by sublimation of ice-rich ground. The stability of subsurface ice changes with the planetary obliquity, generally becoming less stable at lower axial tilt. As a result, the relative rates of sublimation and creep change over time. A landscape evolution model shows that these variations produce internal structure in scalloped depressions, commonly in the form of arcuate ridges, which emerge as depressions resume growth after pausing or slowing. In other scenarios, the formation of internal structure is minimal. Significant uncertainties in past climate and model parameters permit a range of scenarios. Ridges observed in some Martian scalloped depressions could date from obliquity lows or periods of low ice stability occurring <5 Ma, suggesting that the pits are young features and may be actively evolving.

Publication type Article
Publication Subtype Journal Article
Title Effects of varying obliquity on Martian sublimation thermokarst landforms
Series title Icarus
DOI 10.1016/j.icarus.2016.08.031
Volume 281
Year Published 2017
Language English
Publisher Elsevier
Contributing office(s) Astrogeology Science Center
Description 6 p.
First page 115
Last page 120
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