The aureole of Olympus Mons (Mars) as the compound deposit of submarine landslides

The enigmatic deposits building up the Olympus Mons aureole on Mars are likely among the largest landslide remnants in the Solar System. These deposits exhibit an extraordinary run-out distance (up to nearly 700 km), in spite of a fall height some 100 times smaller. After quantifying the mobility of the Olympus Mons aureole lobes it is suggested, based on dynamical considerations and morphological analysis, that the aureole could be the consequence of a series of gigantic subaqueous landslides. In order to bring evidence in favor of this interpretation, comparisons are drawn between the different landslide deposits on Earth and Mars, emphasizing the similarity with the rock avalanches of the Canary Islands and the Hawaii. The results of experimental subaqueous debris flows are also analyzed, and numerical calculations are introduced to simulate the dynamics of flow. In analogy with certain subaqueous landslides on Earth, it is possible that the outstanding run-out of the aureole lobes was a consequence of hydroplaning, a natural lubrication by water during flow. ► Aureole deposits around Olympus Mons on Mars resemble submarine landslides. ► They exhibit high mobility, which implies low friction at the base. ► Idea supported by morphological and numerical analysis and terrestrial analogs. ► Impact on models for water evolution on Mars.