Gravimetric recovery of the moho geometry based on a generalized compensation model

Gravity data used for a recovery of the Moho depths should (optimally) comprise only the gravitational signal of the Moho geometry. This theoretical assumption is typically not required in classical isostatic models, which are applied in gravimetric inverse methods for a recovery of the Moho interface. To overcome this theoretical deficiency, we formulate the gravimetric inverse problem for the consolidated crust-stripped gravity disturbances, which have (theoretically) a maximum correlation with the Moho geometry, while the gravitational contributions of anomalous density structures within the lithosphere and sub-lithosphere mantle (including the core-mantle boundary) should be subtracted from these gravity data. In the absence of a reliable 3-D Earth's density model, our definitions are limited to the crustal and upper mantle density structures. The gravimetric forward modeling technique is applied to compute these gravity data using available models of major known anomalous crustal and upper mantle density structures. The gravimetric inverse problem is defined by means of the (non-linear) Fredholm integral equation of the first kind. After linearization of the integral equation, the solution to the gravimetric inverse problem is given in a frequency domain. The inverse problem is formulated for a generalized crustal compensation model. It implies that the compensation equilibrium is (theoretically) attained by both, the variable depth and density of compensation. A theoretical definition of this generalized crustal compensation model and a formulation of the gravimetric inverse problem for finding the Moho depths are given in this study.