Non-linear effects of the gravity field tensor invariants

Tensor invariants I1 and I2, introduced by Pedersen and Rasmussen (1990), are built combining all six tensor components. As they are independent of the coordinate system, the angular dependence affecting individual tensor components is removed. Pedersen and Rasmussen (1990) show that I1 and I2 respond preferentially to source volume, whereas Dickinson et al. (2009) suggest that I1 may be used for pulling out dominant regional trends and I2 for mapping signature patterns of 3D structures. In this paper we use imaging and inversion methods to the end of analyzing the resolution properties of tensor invariants, invariant ratio, total gradient and other combinations of the tensor components, and we investigate possible non-linear effects that may arise in presence of complex density distributions.