Large loop circuit, combined with high frequency and high current emission system, together with forward and backward modeling, is a useful geophysical prospecting to detect the shallow goaf in coal mines under specific conditions. The goaf in Huangling coal mine is shallow, a theoretical model which is designed based on the actual strata electrical characteristics acquired a good result through forward and backward modeling, sensitive to the anomalies. Application of this method on one coal mine in Huangling area returns a result consistent with the actual strata electrical characteristics, and verified by drilling. It provides a good method for managing the goaf after the mining activities.  

This paper, based on a case study on Linfen coal mine, Shanxi province, uses controlled source audiofrequency magnetotelluric method (CSAMT) and transient electromagnetic method (TEM) to detect the waterfilling goaf in No.2 and No.9+10 coalbeds. CSAMT is sensitive to structure and TEM is sensitive to water, both are combined in effectively detecting the waterfilling goaf and waterbearing faults. This can provide a scientific basis for the management of waterfilling goaf, and ensure the safety and efficient production of coal mines.