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R. D. Lorenz (LPL, U. Arizona)
Titan's hidden landscape can presently only be guessed at. However, some idea of its appearance can be derived from considering the mechanical work performed on the surface by various processes - impact cratering, tidal forces, erosion and tectonics. The impact flux can be estimated from the cratering record elsewhere in the Saturnian system, and tidal effects can be calculated in the usual way. The heat fluxes that drive the other two agents, namely solar and geothermal heating can be estimated from the radiative environment on Titan and from the mass of Titan's rocky core, assuming a typical radiogenic heat production. These heat fluxes can perform work, an upper limit for which is given by the Carnot efficiency; a further useful assumption, since both the fluid mantle and the atmosphere act as heat engines with conductive or radiative losses, is that the engines operate at maximum power conditions (close to a Maximum Entropy Production.)
It is found that erosion (i.e. atmospheric work, including aeolian transportation and shoreline effects of wind-driven waves) is 400x weaker on Titan than on Earth, whereas tectonics (i.e. the output of the mantle heat engine, expressed as earthquakes, mountain-building etc.) are only 50x weaker. Tides and cratering are broadly comparable on the two bodies. These considerations suggest that Titan's landscape will have bizarre complexity, with craters and tectonics featuring prominently and comparably much less eroded than on Earth or Mars.
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Bulletin of the American Astronomical Society, 34, #3< br> © 2002. The American Astronomical Soceity.