Dynamics of Low-Albedo Slope Streaks in Amazonis Planitia, Mars
Kroch, R. (1), Mushkin, A. (2)
1. Open University of Israel
2. Geological Survey of Israel
Low-albedo slope streaks are among the most dynamic surface features observed on present-day Mars. These features exhibit downslope propagation, recurrence, and gradual fading on seasonal to interannual timescales. Despite extensive study, the debate on whether slope-streak formation represents contemporary brine activity, or whether they link to dry mass-wasting phenomena remains unresolved. Resolving this debate has clear implications for our understanding of the habitability and near-surface environmental conditions of present-day Mars.
In this study, we focused on a ~3-km crater diameter crater in Amazonis Planitia (188.9E, 24.0N). We used 22 HiRISE (High Resolution Imaging Science Experiment) high-resolution (0.5 m/pixel ) orbital images that span a period of approximately 5 Martian years to analyze the spatial distribution, growth, fading, recurrence behavior, and geomorphic context of low-albedo slope streaks .
Our results reveal dozens of newly formed slope streaks during the observation period, with individual streak lengths ranging from 40 meters to several hundred meters. New streaks appear fully developed between successive observations separated by as little as 22 sols, after which their morphology remains stable as they gradually fading - indicating rapid formation relative to observation cadence.. In several locations, streaks appear to emanate from dust devil tracks and propagate as fan shaped features downslope In cases where downslope streaks are associated with dust devil activity, the observations are consistent with dry or dominantly mechanical processes acting on a thin, easily disturbed surface layer. More broadly, variability in morphology, growth, and fading behavior across sites may suggests that downslope streaks may reflect a range of surface processes rather than a single formation mechanism.