CSAMT static correction and its application in detection of coal mine goaf

Controlled source audio magnetotelluric(CSAMT) is an effective method for detecting coal mine goaf. As static effects of CSAMT is susceptible to produce due to the influence of shallow inhomogeneity, CSAMT data can be corrected by using the curve-shift method based on the late apparent resistivity data of TEM. It can eliminate the static effect and ensure true resistivity response, and improve the accuracy of data interpretation. Taking the forward model as an example, the effectiveness of this method was verified. This method was applied to detect the goaf in a coal mine in Shanxi. Results of inversion by corrected data coincided well the known data. The theory and practice prove that the correction method is feasible and has good detection effect.