Today's Image of Mars gives us a glimpse of a possible source for the outflow channels that have so drastically shaped the surface of Mars. The large depression in the ground is likely where millions of tons of ground water erupted onto the surface of Mars. This generally occurs due to a rupture of the surface, usually the result of a meteorite impact or past tectonic activity on the planet.
This particular scarp is located in Aurorae Chaos, which is 750 km in diameter and located at the eastern end of Valles Marineris. Aurorae Chaos is the largest discovered area on Mars of chaos terrain, or terrain where cracks, ridges, and plains appear jumbled together in a random and chaotic manner.
This image links to the original captioned image from HiRISE.