This impact would have resulted in significant crustal melting and a general increase in the rate of crustal formation for a period of 40 million years following the impact.[7] Such a large impact would have disturbed the mantle, altering the normal convection currents and causing upwellings which further increase the amount of melting at the impact site.[7] Overall, such an event would actually increase the rate of cooling of the Martian interior.[7] The lack of magnetic anomalies observed in the northern hemisphere could be explained by such an impact, as the shock waves produced might have demagnetized the crust.[7]