Electromagnetic Induction in the Earth by a Non-Symmetric Non-Uniform Source

Abstract

Electromagnetic induction in the earth by a non-symmetric, non-uniform current source is considered. The two-dimensional diffusion equation (for the E-polarization case) is solved by a separation of variables and is related to the current source by a Fourier integral which synthesizes the actual fields from elementary fields over a horizontally stratifield earth. The boundary values for models with embedded conductivity inhomogeneities can be calculated using the above method, and the numerical method of JONES and PRICE (1970) is then used to calculate the perturbations of the fields due to the embedded inhomogeneities. Apparent resistivity curves for a non-symmetric current source and a laterally inhomogeneous conductivity structure are given and compared with results obtained using a uniform inducing field.