High Heat Flux near Miranda’s Inverness Corona Consistent with a Geologically Recent Heating Event

Abstract

Uranus’s moon Miranda has a complex surface reflecting multiple episodes of activity. We estimated the heat flux near Inverness Corona, the youngest terrain on Miranda ( Ma), to gain insight into recent endogenic resurfacing. We modeled flexure associated with Argier Rupes, which separates Inverness from the Cratered Terrain. Our results indicate an elastic thickness of 2.2–3.1 km and a heat flux of 35–140 mW m−2 in this region, assuming Miranda’s lithosphere is composed of pure H2O ice without porosity. Because the formation of the bounding flexure that we analyzed followed the formation of Argier Rupes, our results indicate that Miranda experienced high heat flux in the past Ma. These results are also consistent with heating from a past resonance, possibly an Ariel–Umbriel 5:3 mean motion resonance, estimated to have generated heat fluxes >100 mW m−2 on Miranda. However, if Miranda instead has a porous lithosphere, our heat flux estimates are lower: 34–135 mW m−2 for 5% porosity, 29–114 mW m−2 for 15% porosity, and 20–81 mW m−2 for 25% porosity. Alternatively, if Miranda’s lithosphere includes NH3-hydrates, then our are estimates are even lower, 7–56 mW m−2 without porosity. These estimates decrease further when assuming NH3-hydrates and porosity: 7–54 mW m−2 for 5% porosity, 6–46 mW m−2 for 15% porosity, and 4–32 mW m−2 for 25% porosity. Better constraints on Miranda’s heat fluxes require more information on its ice shell properties.