Heat Effect of Meteorite Impacts on the Degassing of Methane Trapped in Mars' Icy Soil

Abstract

This master's thesis is devoted to assess whether a small impactor can lead to destabilization of clathrates and degassing of methane. Therefore, the increase of temperature as a result of impact energy is theoretically and numerically investigated. First, a discussion on the theoretical model, which is used to calculate the temperature increase following the impact event as a function of the impactor radius, velocity and impact angle, is presented. A comparison study of the two theoretical models considered in this study, Gault-Heitowit and Murnaghan equation of state, is then proposed. The Martian subsurface temperatures are also calculated from the heat equation using the Crank-Nicholson method. The sensitivity of temperature predictions on the thermal conductivity is investigated. The impact-induced temperatures are then added to the initial subsurface temperatures for different case studies. The final step consists of verifying if the temperature at a certain depth allows the destabilization of methane clathrates, and thus degassing of methane, both for equatorial and polar regions, for different thermal conductivities of the subsurface (ranging from 0.039 W/mK to 2.5 W/mK), radii (0.06 m, 0.12 m and 0.20 m) and velocities (8 km/s, 10 km/s and 12 km/s) of the impactor.