A 3D Forward Method for Modeling Magnetic Anomalies Due to Tabular Bodies

This paper presents a new method for computing the magnetic anomaly due to a tabular dipping body, based on approximating a dipping prism by a large number of rectangular prisms. The magnetic anomaly due to this body would be the sum of anomalies resulted from all the small prisms. To test the efficiency of this approximation, we generate the 3-D synthetic anomaly due to a known dipping prism, perform a forward modeling scheme on these data using approximated models, and compare the resulted parameters with the known parameters of the dipping prism. In order to corrupt the synthetic data, we add pseudorandom noise with zero mean and standard deviation of 10% of the datum magnitude. To perform the forward modeling we use a FORTRAN program that inputs the ranges due to different parameters, calculates the anomaly for all possible conditions inside the ranges using the discretized body model, and chooses the best fit parameters. The remanent magnetization information, if available, can be incorporated into the modeling scheme. To show the practicality of this method, we apply the modeling on a real field magnetic data set from Zanjan province in the North-West of Iran.