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Seasonal activity and morphological changes in martian gullies

August 8, 2012

Recent studies of martian dune and non-dune gullies have suggested a seasonal control on present-day gully activity. The timing of current gully activity, especially activity involving the formation or modification of channels (which commonly have been taken as evidence of fluvial processes), has important implications regarding likely gully formation processes and necessary environmental conditions. In this study, we describe the results of frequent meter-scale monitoring of several active gully sites by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO). The aim is to better assess the scope and nature of current morphological changes and to provide improved constraints on timing of gully activity on both dune and non-dune slopes. Our observations indicate that (1) gully formation on Mars is ongoing today and (2) the most significant morphological changes are strongly associated with seasonal frost and defrosting activity. Observed changes include formation of all major components of typical gully landforms, although we have not observed alcove formation in coherent bedrock. These results reduce the need to invoke recent climate change or present-day groundwater seepage to explain the many martian gullies with pristine appearance.

Publication Year 2012
Title Seasonal activity and morphological changes in martian gullies
DOI 10.1016/j.icarus.2012.04.005
Authors Colin M. Dundas, Serina Diniega, Candice J. Hansen, Shane Byrne, Alfred S. McEwen
Publication Type Article
Publication Subtype Journal Article
Series Title Icarus
Index ID 70039360
Record Source USGS Publications Warehouse
USGS Organization Astrogeology Science Center