| 摘要 |
In the method, the mutually orthogonal, horizontal, magnetic and electrical components ?x, Hy, Ex, Ey for the intensity of the Earth's natural electromagnetic field are measured. The impedance values Z1=Ex/Hy and Z2=E?/H? are calculated in a processing device. On the basis of the impedance values, changes over time in the electrical resistances ??1(Z1,t) and ??2(Z2,t) are determined, and, on the basis of sudden changes in said electrical resistances that exceed previously measured reference data ?ref1(Z1,t), ?ref2(Z2,t) by more than 5 times, a judgment is made in respect of the preparatory phase of faults in the upper part of a geological section UPS over a time t of from 1 to 15 days. |
