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Seasonally active frost‐dust avalanches on a north polar scarp of Mars captured by HiRISE
Author(s) -
Russell Patrick,
Thomas Nicolas,
Byrne Shane,
Herkenhoff Kenneth,
Fishbaugh Kathryn,
Bridges Nathan,
Okubo Chris,
Milazzo Moses,
Daubar Ingrid,
Hansen Candice,
McEwen Alfred
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035790
Subject(s) - fault scarp , geology , mars exploration program , martian , mass wasting , aeolian processes , polar , context (archaeology) , snow , frost (temperature) , astrobiology , atmospheric sciences , earth science , geomorphology , paleontology , sediment , fault (geology) , physics , astronomy
North‐polar temporal monitoring by the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars has discovered new, dramatic examples that Mars' CO 2 ‐dominated seasonal volatile cycle is not limited to quiet deposition and sublimation of frost. In early northern martian spring, 2008, HiRISE captured several cases of CO 2 frost and dust cascading down a steep, polar scarp in discrete clouds. Analysis of morphology and process reveals these events to be similar to terrestrial powder avalanches, sluffs, and falls of loose, dry snow. Potential material sources and initiating mechanisms are discussed in the context of the Martian polar spring environment and of additional, active, aeolian processes observed on the plateau above the scarp. The scarp events are identified as a trigger for mass wasting of bright, fractured layers within the basal unit, and may indirectly influence the retreat rate of steep polar scarps in competing ways.