Olympus Mons the -diameter Pangboche crater (). The craters are notable for being two of several suspected source areas for shergottites, the most abundant class of Martian meteorites. As a shield volcano, Olympus Mons resembles the shape of the large volcanoes making up the Hawaiian Islands. The edifice is about wide. Because the mountain is so large, with complex structure at its edges, allocating a height to it is difficult. Olympus Mons stands above the Mars global datum, and its local relief, from the foot of the cliffs which form its northwest margin to its peak, is nearly (a little over twice
Olympus Mons This inhibition of southeasterly basal spreading in Olympus Mons could account for the structural and topographic asymmetry of the mountain. Numerical models of particle dynamics involving lateral differences in friction along the base of Olympus Mons have been shown to reproduce the volcano's present shape and asymmetry fairly well. It has been speculated that the detachment along the weak layers was aided by the presence of high-pressure water in the sediment pore spaces, which would have interesting astrobiological implications. If water-saturated zones still exist in sediments under the volcano, they would likely have been kept warm by a high geothermal