J. Geophys. Res.http://doi.org/h3r (2012)

Credit: © NASA/JPL

The surface of Saturn's moon Titan is less than 1 billion years old, with mechanisms ranging from ice volcanism to widespread erosion invoked to explain its resurfacing. An analysis of Cassini radar imagery, however, indicates little surface modification by fluvial erosion in some regions.

Because topographic data on Titan are currently limited, Benjamin Black at the Massachusetts Institute of Technology and colleagues devised a method to estimate erosional modification of a surface by quantifying the shapes of drainage networks. They calibrated the method with a numerical landscape evolution model, and then validated their approach by comparisons with terrestrial fluvial networks where the exhumation history is known. Applying their technique to four regions with prominent drainage networks on Titan, they estimate that regionally averaged fluvial erosion in these regions reflects only 0.5–9% of the initial topographic relief.

Assuming surface ages from crater counts, this implies that long-term rates of fluvial erosion are much slower than on Earth. Unless some regions on Titan have been resurfaced more recently than the global average, other mechanisms are required to explain Titan's resurfacing.