Credit: Lujendra Ojha, et al.

New research suggests that recurring slope lineae (RSL) on Mars might be causing landslides, and/or the landslides are being sparked by ice-clouds.

RSL are dark, fingerlike features that creep down steep Martian slopes in warm weather and continue to puzzle scientists.

“Seasonal Slumps in Juventae Chasma, Mars” has been published in the American Geophysical Union’s Journal of Geophysical Research – Planets, new work led by Lujendra Ojha in the Department of Earth and Planetary Sciences at the Johns Hopkins University, Baltimore, Maryland.

Seasonal slumps

Ojha and his colleagues have detected dark topographic slumps several meters wide, tens of meters in length and up to a meter in depth on the slopes of Juventae Chasma in Valles Marineris.

These slumps usually originate near the terminal points of RSL. Near their initiation points, the slumps have topographic depressions due to the removal of materials; near their lowermost reaches, new materials are deposited in lobes.

Over the course of three Mars years, ten active slumps have been observed in that area, all of which formed in or near the same season.

Credit: Lujendra Ojha, et al.

Onboard the Mars Reconnaissance Orbiter (MRO), the spacecraft’s Mars Color Imager (MARCI) show low-altitude atmospheric obscurations confined within the topography of the Valles Marineris and Juventae Chasma in the seasons when the slumps form.

Water ice

In one instance, data from the MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and MARCI show evidence of water ice in the atmospheric obscuration – likely due to the formation of a low-level afternoon cloud above a dust storm, or mixing of condensate clouds with a diffuse dust cloud, the research team reports.

Mars Reconnaissance Orbiter
Credit: NASA

“The presence of atmospheric obscurations with H2O ice near times when the slumps form is intriguing, but no direct evidence currently exists to support that they aid in slump formation,” they report.

Further monitoring of this site, the investigators conclude, will help establish if RSL and/or atmospheric events play a role in the creation of contemporary slumps.

The research paper is available here at:

http://onlinelibrary.wiley.com/doi/10.1002/2017JE005375/abstract

Leave a Reply

Griffith Observatory Event