Rapid gravity computations for two-dimensional bodies with application to the Mendocino submarine fracture zone

Expressions are derived for the vertical and horizontal components of the gravitational attraction due to a two-dimensional body of arbitrary shape by approximating it to an n-sided polygon. These expressions are put in forms suitable for solution by a high-speed digital computer. As an example of the application of this method, the crustal section across the Mendocino fracture zone is deduced from the gravity anomalies. Assuming the crust to consist of a single homogeneous layer, overlain by water and sediment, it is found to be about three km thicker to the north of the fracture zone than to the south of it.