Estimating Layered-Earth Conductivity and Thickness with Multiple-Array Electromagnetic Instruments

Since 1999, dual-array electromagnetic (EM) instruments have been used to identify the presence of layering of electrical conductivity in<br>the upper-few metres of the earth. Newly introduced instruments with multiple arrays can provide more detailed information about conductive<br>layering. Examples and a simulation show that the detailed measurements from the multiple-array instruments can estimate the conductivity<br>and thickness of a surficial layer, as well as the conductivity of the earth that underlies the layer.