Rapid 3-D forward model of potential fields with application to the Palinuro Seamount magnetic anomaly (southern Tyrrhenian Sea, Italy)

Abstract

We show a set of forward model equations in the Fourier domain for calculating the 3-D gravity and magnetic anomalies of a given 3-D distribution of density or magnetization. One property of the potential field equations is that they are given by convolution products, providing a very simple analytic expression in the Fourier domain. Under this assumption, the domain of the density or magnetization parameters is connected by a biunivoc relationship with the data space, and potential field anomalies can be seen as filtered versions of the corresponding density or magnetization distributions. A very fine spatial discretization can be obtained by using a large number of points within a unique 3-D grid, where both the source distributions and field data are defined. The main advantage of this formulation is that it dramatically reduces execution times, providing a very fast forward model tool useful for modeling anomalies at different altitudes. We use this method to evaluate an average magnetization of 8 A/m for the Palinuro Seamount in the Tyrrhenian Sea (southern Italy), thus performing a joint interpretation of morphological and newly acquired magnetic data.