Elastic Thickness and Heat Flux Variations on Mercury from Thermal Evolution Modeling

Kurzfassung

Recent studies of the data from the MESSENGER mission implied that volcanic activity on the surface of Mercury persisted for longer than expected. In order to explain this long-lasting activity on Mercury, studies advanced the presence of a thermal insulating layer enabling the mantle to be warmer for an extended period, here being the mega-regolith. In this study we coupled the presence of a mega regolith layer on Mercury with different models of crust distribution in our mantle convection code in order to quantify their effect on the heat flow through the silicate shell during its thermal evolution. We were also able to compute local elastic lithosphere thickness values during its early evolution. Our results indicate that the surface temperature variations of Mercury are predominant on its surface heat flow pattern, and that crustal distribution as well as its enrichment create a more local and smaller scale effect. Concerning the computation of local elastic thickness for the Caloris Basin and Discovery Rupes, our results seem to be in the field of the values suggested by the literature. Further studies on the exact age of formation of given geological features on the surface of Mercury, as well as the elastic thickness at their time of formation would help us improve our models.