Giant impacts have been suggested to explain various characteristics of
terrestrial planets and their moons. However, so far in most models only the
immediate effects of the collisions have been considered, while the long-term
interior evolution of the impacted planets was not studied. Here we present a
new approach, combining 3-D shock physics collision calculations with 3-D
thermochemical interior evolution models. We apply the combined methods to a
demonstration example of a giant impact on a Mars-sized body, using typical
collisional parameters from previous studies. While the material parameters
(equation of state, rheology model) used in the impact simulations can have
some effect on the long-term evolution, we find that the impact angle is the
most crucial parameter for the resulting spatial distribution of the newly
formed crust. The results indicate that a dichotomous crustal pattern can form
after a head-on collision, while this is not the case when considering a more
likely grazing collision. Our results underline that end-to-end 3-D
calculations of the entire process are required to study in the future the
effects of large-scale impacts on the evolution of planetary interiors.Comment: 29 pages, 10 figures, accepted for publication in Icaru