Ravi Vallis is an ancient outflow channel, the source of which originates from the Aromatum Chaos depression, in the Margaritifer Sinus quadrangle (MC-19) region on Mars, located at 0.2° S and 40.7 W°. It is 205.5 km long and was named after the Ravi River, an ancient Pakistani river. The Ravi Vallis outflow channel, and the neighbouring deep depression at Aromatum Chaos, are thought to have been caused by volcano-ice interactions underneath the surface, which pierced the underground aquifer. This released large amounts of water, causing a catastrophic flood event, which is thought to have lasted between 2 and 10 weeks.
^Leask, H. J., L. Wilson, and K. L. Mitchell (2006), Formation of Ravi Vallis outflow channel, Mars: Morphological development, water discharge, and duration estimates, J. Geophys. Res., 111, E08070, doi:10.1029/2005JE002550.
^Leask, H. J., L. Wilson, and K. L. Mitchell (2006), Formation of Aromatum Chaos, Mars: Morphological development as a result of volcano-ice interactions, J. Geophys. Res., 111, E08071, doi:10.1029/2005JE002549.