A stress interpretation scheme applied to lunar gravity and topography data

Abstract

We present an approach of the inverse gravimetric problem that allows the gravity to be directly related to the deviatoric stresses without any rheological assumptions. In this approach a new set of parameters is considered: (1) the density variations over equipotential surfaces and the height of interfaces above the corresponding equipotential surfaces and (2) the stress difference. The method is applied to lunar topographic and gravimetric data that are interpreted in term of transversally isotropic deviatoric stress within the Moon. It also provides inference on density and crustal thickness variations. The estimated lateral variation in deviatoric stress is about 500 bars within the crust and upper mantle. In the crust, because of topography, the strongest stress differences take place on the far side, with large lateral compressions beneath the south pole–Aitken basin. Vertical compression under the mascons of the nearside is the main feature within the upper mantle.