Landslides Inside a Crater

Landslides Inside a Crater, a photo by Lunar and Planetary Institute on Flickr.

Via Flickr:
Craters once brim-full with sediments and water have long since drained dry, but traces of their former lives as muddy lakes remain in the martian desert. This image was taken on 15 January 2013 by ESA’s Mars Express, and features a region just a few degrees south of the equator within the ancient southern highlands of Mars. The unnamed region lies immediately to the north of an ancient riverbed known as Tagus Valles and east of Tinto Valles and Palos crater.

Numerous landslides have occurred within this crater, perhaps facilitated by the presence of water weakening the crater walls. Grooves etched into the crater’s inner walls mark the paths of tumbling rocks, while larger piles of material have slumped enmasse to litter the crater floor.

But it’s not just water that has played a role in this region; volcanic eruptions have also had an effect. A dark layer of fine-grained ash covers the top left corner of the main image that may have been deposited from the Elysium volcanic province to the northeast. Over time, the ash was redistributed by wind, and buried deposits exposed in localized areas by erosion.