Geomorphological evidence for a dry dust avalanche origin of slope streaks on Mars

Nature Geoscience



Mars has several different types of slope feature that resemble aqueous flows. However, the current cold, dry conditions are inimical to liquid water, resulting in uncertainty about its role in modern surface processes. Dark slope streaks were among the first distinctive young slope features to be identified on Mars and the first with activity seen in orbital images. They form markings on steep slopes that can persist for decades, and the role of water in their formation remains a matter of debate. Here I analyse the geomorphic features of new slope streaks using high-resolution orbital images. Comparison of images before and after streak formation reveal how this process affects the surface and provides information about the cause. These observations demonstrate that slope streaks erode and deposit material in some instances. They also reveal that streaks can jump slopes and may be erosive very near their termini. These observations support a formation model where dark slope streaks form as ground-hugging, low-density avalanches of dry surface dust. Such streaks need not be treated as Special Regions for planetary protection.

Publication type Article
Publication Subtype Journal Article
Title Geomorphological evidence for a dry dust avalanche origin of slope streaks on Mars
Series title Nature Geoscience
DOI 10.1038/s41561-020-0598-x
Volume 13
Year Published 2020
Language English
Publisher Nature Publishing Group
Contributing office(s) Astrogeology Science Center
Description 4 p.
First page 473
Last page 476
Other Geospatial Mars
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