The dry and barren landscape on Mars is often compared to dry and desolate deserts on Earth, but McGovern et al. have chosen a tropical paradise, the Hawaiian islands, for a terrestrial analogy to explain the evolution of Olympus Mons, which is the largest known volcano (about 23 km in height and 600 km in diameter) in the solar system. It is partly bounded by an irregular scarp as high as 10 km, and lobes of hummocky terrain, which are called aureole deposits, funnel outward from this scarp. The aureole deposits contain remnants of formerly continuous volcanic flow units and morphologically resemble landslides around the edges of Hawaiian volcanoes. The authors suggest that, in similar fashion, Olympus Mons may have grown and spread by basal detachment faults. In Hawaii, the landslides are lubricated by high pore fluid pressure on the faults and are mostly submarine, which poses the question: Was Olympus Mons once a fluid paradise, too? - LR
J. Geophys. Res. 109, 10.1029/2004JE002258 (2004).
