Evidence for Recent Groundwater Seepage and Surface Runoff on Mars
Michael C. Malin,
*
Kenneth
S. Edgett
Relatively young landforms on Mars, seen in high-resolution images
acquired by the Mars Global Surveyor Mars Orbiter Camera since March
1999, suggest the presence of sources of liquid water at shallow depths
beneath the martian surface. Found at middle and high martian latitudes
(particularly in the southern hemisphere), gullies within the
walls of a very small number of impact craters, south polar pits, and
two of the larger martian valleys display geomorphic features that can
be explained by processes associated with groundwater seepage and
surface runoff. The relative youth of the landforms is indicated by the
superposition of the gullies on otherwise geologically young surfaces
and by the absence of superimposed landforms or cross-cutting features,
including impact craters, small polygons, and eolian dunes. The limited
size and geographic distribution of the features argue for constrained source reservoirs.
Malin Space Science Systems, Post Office Box 910148, San Diego, CA
92191-0148, USA.
*
To whom correspondence should be addressed.
