Olympus Mons Summit

The circular feature in this VIS image is part of the summit of Olympus Mons. Large volcanic craters known as calderas are located at the summits of all the Tharsis volcanoes. These calderas are produced by massive volcanic explosions and collapse. Scarps and extensional features (graben) record multiple stages of caldera collapse at the summit of Olympus Mons. Olympus Mons is the largest volcano in the solar system, reaching heights over 25 km (16 miles) tall from base to summit, with the base covering an area as large as the state of Arizona. For comparison, Mauna Loa is 9 km (5.5 miles) tall measured from its base on the sea floor.