Flexure on Dione: Investigating subsurface structure and thermal history

Using stereo generated topography of Dione, a moon of Saturn, we infer flexure across a prominent ridge on the leading hemisphere to estimate local elastic thickness and place constraints on Dione’s thermal evolution. Assuming topography is related to the flexing of a broken elastic plate, we estimate an effective elastic thickness of 3.5 ± 1 km. This local estimate is in good agreement with global values derived from long wavelength topography. Corresponding heat fluxes of 25–60 mW/m2 are much greater than those expected for a body heated solely from radioactive decay. It would be possible to generate our inferred heat flux values via tidal heating at close to the current orbital eccentricity of Dione, but only if a subsurface ocean were present at the time of flexural deformation.