Joint Inversion of Gravity Gradient Tensor at Vredefort Impact Crater

Abstract

In recent years, Gravity Gradient Tensor (GGT) has been successfully used in applied and environmental geophysics, also in light of the development of gradiometers. In this paper, we aim at analysing the inversion, either joint or separate, of different GGT components and of the sole gravity field vertical component. We perform our analysis by inspection of the Picard Plot, a well-known Singular Value Decomposition tool, and employ both synthetic data and gradiometer measurements carried out at the Vredefort structure, South Africa. We show that the main factors controlling the quality of the inversion are algebraic ambiguity and signal-to-noise ratio. Provided that algebraic ambiguity is kept low – by different combinations of GGT components and/or only gravity field data – the choice of components involved in the inversion is non-crucial to the quality of the reconstructions. Nonetheless, the use gradiometers allows a quicker and more effective way, with respect to the sole gravity field, to improve algebraic ambiguity.