The alignment of the three shield volcanoes that make up the Tharsis Montes is clearly evident in this view. The three volcanoes are named Ascraeus Mons (slides #5 and #6), Pavonis Mons (slide #7), and Arsia Mons (slide #8), going from north to south. The three volcanoes are each somewhat smaller than Olympus Mons, varying from 350 to 450 km (210 to 270 mi) in horizontal extent and each rising about 15 km (9 mi) above the surrounding plains. The Tharsis Montes are located on the crest of a broad uplift of the martian crust so that their summits are at about the same elevation as the summit of Olympus Mons. The fractures southeast of Pavonis Mons are named Noctis Labyrinthus; this region merges with the enormous Valles Marineris canyon system to the east. The colors shown here are similar to the actual color of Mars but have been enhanced to emphasize subtle variations. The white patches around the lower flanks of the volcanoes are thin clouds that commonly occur near the volcanoes.
0 N, 100 W; portion of a color digital mosaic generated by Al McEwen at U.S. Geological Survey, Flagstaff, AZ.