Abstract：The electrical column structure model is usually used to represent the longitudinal variation of electrical characteristics within a region. When we analyze the overall electrical characteristics by regional MT sounding data, it is difficult to get satisfactory regional electric characteristics through one-dimensional inversion by using single TE, TM, and mean of TE with TM data conventionally. The equivalent apparent resistivity method is used to calculate equivalent apparent resistivity below the station based on the impedance tensor plural rotate invariantly. The calculation result is not dependent on the change of surface measuring azimuth. In areas with very complex geological conditions, the use of equivalent apparent resistivity method can obtain the longitudinal electrical structure of the region. Taking northeast MT array "standard station" as an example, the authors designed a very complex three-dimensional model according to the measured data. Studies show that the equivalent apparent resistivity method has better resolution in the transverse direction and the longitudinal direction, as shown by model forward and inversion calculation and comparison experiments. The authors applied the method to the construction of electrical column structure at the northeast MT array standard station and achieved a good application effect.
