Abstract
Impedance relations for non-uniform conductors with plane and spherical boundaries are derived which show the similarity between the magnetic potential method and the magnetotelluric method. The impedance relations are so presented that they can be used for any number of layers inside the earth, each representing a different conductivity distribution. Calculations of impedance and phase values for conductors with plane boundaries show that the horizontal wave length of the source can be assumed to be infinite when determining moderate resistivity distributions at shallow depths. Similar calculations for conductors with plane and spherical boundaries for a few conductivity distributions show that the effect of the earth's sphericity can be neglected for periods less than a day when determining conductivity distribution by the magnetotelluric method.
