Computation of the Magnetic Anomalies Caused by Two-Dimensional Bodies

The magnetic anomaly of a two-dimensional body of uniform magnetization and arbitrary shape can be expressed compactly in terms of the vertical and horizontal derivatives of the corresponding gravity anomaly and an angle β which incorporates both the direction of magnetization and the direction in which the observed magnetic anomaly component is measured. The formula is useful for computing families of curves. By an extended use of the formulation, computation of the conjugate harmonic function to the observed magnetic anomaly makes it possible to compute the anomaly for different values of β without knowledge of the shape of the body. The simplicity of the formulation cannot be extended to bodies of three-dimensional shape but computational short cuts are nevertheless available.