Courtesy NASA/JPL-Caltech

The Tharsis region on Mars is an enormous volcanic upland located on Mars' equator, at the western end of Valles Marineris.

It contains the Tharsis Bulge, on which some of the solar system's largest volcanos are located. Olympus Mons is at top left. At center, diagonally from top to bottom are Ascraeus Mons, Pavonis Mons and Arsia Mons (collectively known as Tharsis Montes). Tharsis Bulge rises up to 10 kilometers above its surroundings and covers 30 million square kilometers. It is thought to have been formed by a mantle plume over a period of about a hundred million years during the Noachian epoch.

The vast size of the Tharsis Bulge had a great impact on the geology of Mars. Tharsis is surrounded by a ring-shaped topological depression called the Tharsis trough, and on the opposite side of the planet is a smaller bulge called Arabia Terra which likely formed as a result of the weight of Tharsis. These features were a major influence on the formation of Mars' drainage valleys, most of which formed in the late Noachian. The large quantities of carbon dioxide and water vapor that could have been outgassed by Tharsis magma may have also played a significant role in Mars' wet period; Roger J. Phillips calculated in 2001 that it could have formed a 1.5-bar carbon dioxide atmosphere and a global layer of water that was 120 meters thick (assuming uniform distribution).

Alba Patera is a unique volcanic feature to the north of the Tharsis region.

External links

• Researchers pinpoint region responsible for Mars' heyday