Back to Search
Start Over
Dune-slope activity due to frost and wind throughout the north polar erg, Mars
- Publication Year :
- 2017
- Publisher :
- Geological Society of London, 2017.
-
Abstract
- Repeat, high-resolution imaging of dunes within the Martian north polar erg have shown that these dune slopes are very active, with alcoves forming along the dune brink each Mars year. In some areas, a few hundred cubic metres of downslope sand movement have been observed, sometimes moving the dune brink ‘backwards’. Based on morphological and activity-timing similarities of these north polar features to southern dune gullies, identifying the processes forming these features is likely to have relevance for understanding the general evolution/modification of dune gullies. To determine alcove-formation model constraints, we have surveyed seven dune fields, each over 1–4 Mars winters. Consistent with earlier reports, we found that alcove-formation activity occurs during the autumn–winter seasons, before or while the stable seasonal frost layer is deposited. We propose a new model in which alcove formation occurs during the autumn, and springtime sublimation activity then enhances the feature. Summertime winds blow sand into the new alcoves, erasing small alcoves over a few Mars years. Based on the observed rate of alcove erasure, we estimated the effective aeolian sand transport flux. From this, we proposed that alcove formation may account for 2–20% of the total sand movement within these dune fields.
- Subjects :
- Martian
010504 meteorology & atmospheric sciences
Geology
Ocean Engineering
Mars Exploration Program
Atmospheric sciences
01 natural sciences
Article
Aeolian sand
0103 physical sciences
Polar
010303 astronomy & astrophysics
Geomorphology
Alcove
0105 earth and related environmental sciences
Water Science and Technology
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....35aca42e129e071e4c9fde26459d62ee
- Full Text :
- https://doi.org/10.6084/m9.figshare.5624866