Climbing Dunes Escaping A Crater In Aonia Terra On Mars

One of the fundamental questions of any sedimentary system relates to where the sediment is coming from. Craters on Mars, or any depressions, primarily fill the role of sediment sinks, but they can also serve as sources for sand and other materials.

However, dunes and other sandy bedforms on Mars have a propensity for migrating up steep slopes including the cliffs of Valles Marineris.

This stereo pair and DTM reveal one such location where sandy bedforms appear to be crawling out of a crater. This crater is near 1 kilometer deep and shows steep slopes particularly on the south face. For example, we can see gully systems have carved shallow channels in the face of this dune, while nearby slopes are piling up debris along the cliff edge (500 meters wide). Nevertheless, there are dunes climbing and exiting the crater towards the north where an even larger sand erg is found.

In this 4.6-kilometer wide view, we can see a topographic profile across the climbing dunes and onto the plateau above. Thus, this DTM from HiRISE shows an example where the crater serves as a sand source, rather than sink, for some regional windblown systems.

ID: ESP_039380_1290
date: 20 December 2014
altitude: 250 km

https://uahirise.org/hipod/ESP_039380_1290NASA/JPL-Caltech/UArizona