Layers in a Scarp on Olympus Mons

This observation shows a small portion of the scarp (cliff) that surrounds the largest volcano in the solar system, Olympus Mons.

The scarp is of unknown origin. It may have formed from faulting or other tectonic processes resulting from the heavy loading of the Martian crust in this location. The bottom of the image shows the cratered flanks of Olympus Mons.

Olympus Mons is a large shield volcano, like the Hawaiian volcanoes on Earth. Shield volcanoes have very shallow slopes and gentle eruptions. The Hawaiian volcanoes form when a plate of crust moves over a hot spot. The hot spot produces magma that gradually forms the volcanoes. Since Earth has plate tectonics, the crustal plate moves over the hot spot producing a chain of volcanoes.

Mars does not have plate tectonics, which causes the magma to build a volcano in one location making Olympus Mons so large.

Written by: Kelly Kolb   (10 February 2010)

This is a stereo pair with PSP_001630_2015 .

More info and image formats at

Image: NASA/JPL/University of Arizona