Definition for Olympus Mons
From Biology Forums Dictionary
Olympus Mons, located on the planet Mars, is by far the tallest volcano in the solar system, rising higher than three Mount Everests and spanning the width of the entire Hawaiian island chain. It is the largest of the major Tharsis volcanoes, rising 15.5 miles (25 km) and stretching over nearly 340 miles (550 km) east-west.
Olympus Mons is surrounded by a well-defined scarp that is up to 4 miles (6 km) high. Lava flows drape over the scarp in places.
Much of the plains surrounding the volcano are covered by the ridged and grooved 'aureole' of Olympus Mons. The origin of the aureole is controversial, but may be related to gravity sliding off of the flanks of an ancestral volcano.
The summit caldera (central depression), a composite of as many as seven roughly circular collapse depressions, is 41 by 52 miles (66 by 83 km) across. It probably formed from recurrent collapse following drainage of magma resulting from flank eruptions.
