English: After the initial impact, high heat flux and high water content would have favored viscous relaxation to take place. The crust becomes more ductile. The basin topography of the craters is thus subjected to greater stress due to self-gravitation, which further drive crustal flow and decay of relief. However, this case may not work for giant impact craters such as Hellas, Utopia, Argyre and Isidis basins.