Dawson, Trevor William2016-09-092016-09-0919792016-09-09http://hdl.handle.net/1828/7532A fairly general method for studying electromagnetic induction in cases where any lateral variations in conductivity are confined to the near-surface region is developed using the thin-sheet technique. The significant feature is that extended anomalies, subject only to the restriction that well-defined two-dimensional problems are approached at infinity, can be handled. The approximate boundary condition is that gradients parallel to the coordinate axes vanish at infinity.enAvailable to the World Wide Webelectromagnetic inductionthin sheetsthree-dimensional integral equationThesis