Assessing the role of tidal heating and insolation on lateral heterogeneity in Europa’s ice shell

Observations from past missions, including NASA’s Galileo, reveal active ice tectonics and a subsurface ocean on Europa, implying material recycling within the ice shell, possible exchange with the underlying ocean, and thus the potential conditions for habitability. Constraining the structure of Europa’s ice shell is therefore a primary objective of NASA’s Europa Clipper mission, as it controls the efficacy and efficiency of the material exchanged between the surface and the ocean. However, the mechanisms that govern the mass exchange and shape the internal structure of Europa’s ice shell remain uncertain. These are likely influenced by the spatial distribution of heat sources on Europa, with insolation raising surface temperatures near the equator while tidal heating is strongest toward the poles. Because insolation and tidal heating produce opposing latitudinal temperature patterns, their combined effects may either suppress or enhance lateral variations within the ice shell. To investigate the combined effects of insolation and tidal heating, we present numerical models of Europa’s ice shell that include heterogeneous tidal heating and surface temperature, coupled with visco-elasto-plastic deformation and composite ice rheology. We investigate how these heat sources influence convection within the possible range of ice shell thickness, and explore their effects on the global distribution of heat flow, stress accumulation, and topography at the ice surface of Europa. Our results provide new insights into lateral variations in internal structure and the evolution of surface deformation in Europa’s ice shell, with implications for ice shell tectonics and surface–interior coupling.