Fig. 3. The apparent resistivities (ohm m) and phases (degree) as a function of log10 periods (second) computed from the off-diagonal impedance tensor at seven locations acquired in the locations shown in Fig. 2. Red is xy and blue is yx mode. The circles and error bars are from field measurement, and the solid lines are the calculated responses generated from the inverted model shown in Figs. 5–7. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)