Influence of self-demagnetization effect on data interpretation in strongly magnetic environments

Abstract

In this paper, we discuss the influence of the self-demagnetization effect on magnetic data and present an alternative means of quantitatively interpreting such data in highly magnetic environments. In particular, we present two important results based on simulation which one might consider in their interpretation of magnetic data when self-demagnetization is present. First, current methods for estimating total magnetization, which are typically applied to the problem of remanent magnetization, do not reliably recover this parameter when the anomalous source bodies have high magnetic susceptibilities. And second, a single value estimation of total magnetization does not provide adequate information to properly resolve subsurface geology through inversion. Numerical experiments demonstrate that directly inverting amplitude data, calculated from magnetic data yet weakly-dependent on magnetization direction, produces superior results when interpreting data generated in terrain with high magnetic susceptibilities.