Magellan
A forward marine magnetic modeling program

General Overview

Magellan is based on Talwani's (1964) method of 2-D bodies. This method applies both for gravity and magnetic modeling, but Magellan only deals with the magnetic part of the method.

The oceanic floor is assumed to be a set of parallelepipeds that extend infinitely along the ridge, where sea floor spreading is taking place (Fig. 1). This assumption reduces a 3-D problem into a 2-D problem, making it easier to solve. Here we use a right-handed (positive) cartesian coordinate system where the ridge extends infinitely along the y-axis and the positive z-axis is down. Henceforth the depth that is measured is positive. Also, the shiptracks are generally run perpendicular to the ridge, that is along the x-axis. The parallelepipeds are defined by the bathymetry of the oceanic floor and their magnetization is assumed to be homogeneous (that is not directionally dependent).

Fig 1. Graphical representation of the coordinate system used. The hexagonal shaped polygon is defined by the bathymetry and the thickness of the magnetized layer.

The thickness of the magnetized layer is by default 500m but the user has the freedom to change it.

The Equations and Their Implementation