UNDERGROUND ELECTROMAGNETIC SURVEILLANCE METHOD, DEVICE AND INFORMATION STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an underground electromagnetic surveillance method capable of accurately grasping a monoclinic structure of a bedrock which is hard to accurately grasp by TDEM surveillance. SOLUTION: In this underground electromagnetic surveillance method, electromagnetic surveillance of cutting off energization to a transmission loop, producing a smoke ring phenomenon in which an eddy current propagates to the bedrock, and measuring attenuation of the eddy current as a change of a time function of an electromagnetic field using a receiving loop is repeatedly performed along a plurality of measurement points in a ground surface side (S1-S4). A geological structure of the bedrock is calculated on the basis of measurement data obtained at each measurement point (S5 and S6). Particularly, in the step S6, a process is performed determining positions of the monocline structure in relation to measurement points where measured values change.