Lateral-Wave Propagation of Electromagnetic Waves in the Lithosphere

The possibility of lateral-wave propagation of electromagnetic waves between horizontal electric dipoles near the floor of the ocean is reviewed. The general exact integrals for the radial electric field, which is the most useful component for lateral-wave transmission, are evaluated numerically for a range of possible conductivities of the lithospheric rock. Graphs and contour diagrams are shown and discussed for frequencies from 10 Hz to 1 GHz and radial distances from 0.1 to 100 km. Conditions under which very low frequencies provide the greatest range are defined, and also conditions under which a high-frequency window is available that offers by far the greatest radial range.