Apparent resistivity calculations for laterally inhomogeneous structures

Abstract

Apparent resistivity calculations are made for two-dimensional models of a semi-infinite conducting half-plane with conductivity inhomogeneities of finite lateral extent in one direction and are compared with similar calculations over a semi-infinite two-layered medium. The models are solved by a numerical technique for both E-polarization and H-polarization cases. The results show that at a particular period the calculated value of the apparent resistivity over the centre of the finite region approaches the value for a two-layered semi-infinite conducting medium as the width of the finite region is increased. In the E-polarization case, the apparent resistivity curves, which give the variation of the apparent resistivity with the period, over the finite structure differ from the curves for the two-layered case for the shorter periods in the range considered and approach the curves for the layered case for longer periods. For the H-polarization, the apparent resistivity curves appear to approach the curves for the layered case for shorter periods, but deviate considerably from those for the layered case at longer periods.