ABSTRACT
Electromagnetic induction (EMI) has been used in geophysics for decades in the exploration for bodies of metallic ore. This chapter provides various comparisons that have been made between electromagnetic induction and static magnetic effects. It presents methods of displaying EMI data, the manner in which this data can be acquired, and depth estimation based on changes in the EMI response with measurement position. Although the element of time is present in EMI measurements, either through the operating frequency selected or the direct transient response, these aspects are remarkably similar to those discussed for gravity and magnetometry. The chapter establishes that, for a magnetic force to exist, there must be two magnets. A hypothetical force caused by a single magnet can be defined as the force that a magnet would exert on a unit south pole. This imaginary force was referred to as a magnetic field.
