Comprehensive observations and geostatistics of slope streaks within the Olympus Mons aureole

Icarus, Journal Year: 2024, Volume and Issue: 415, P. 116061 - 116061

Published: March 20, 2024

Slope streaks (SS) are enigmatic linear features characterized by relatively low-albedo that appear and fade on high-albedo slopes Mars. Despite numerous hypotheses proposed to explain their formation, the primary mechanism behind SS remains elusive. Here, we examine 702 using 32 multitemporal Context Imager (CTX) images mesoscale modeling data obtained from a site (centered at 31.230°N, 216.281°E) in Olympus Mons Aureole region. Our investigation revealed several key findings shed light dynamics of formation fading. We discovered significant preference for south-facing (equator-facing) compared north-facing slopes, with being over seven times more likely occur former. Furthermore, was found be seasonal significantly enhanced factor ~6 near equinoxes (from solar longitude Ls 337°-42° 136°-227°) other year. analysis also correlation between rates fading, scree exhibited fastest-fading experiencing highest newly-formed SS. Additionally, measured median starting stopping 23.4° 14.9°, respectively, below angle repose sand. These low suggest necessity an energetic trigger initiate formation. Infrared spectroscopy principal distinction material inside outside lies reduced abundance dust within streak. Notably, this demonstrates (a 29.6% increase new per Mars year) fading 12% ever quantified. elevated may attributed site's topography, which facilitates calm surficial nighttime winds throughout year, leading widespread deposition. Daytime downhill ridgelines S-facing then movement newly deposited aggregates or alternatively, Knudsen pump phenomenon could serve as potential propose is inhibited during northern summer solstice season due clear aphelion atmosphere, limits Similarly, lack triggering activity winter moderate daytime winds. Overall, our consistent wind-triggered dry avalanche hypothesis plausible explanation

Language: Английский

Albedo analysis of dust devil-induced slope streaks and tracks on Mars

Icarus, Journal Year: 2024, Volume and Issue: 423, P. 116270 - 116270

Published: Aug. 22, 2024

Language: Английский