CHARACTERISTIC INFLUENCES OF DIFFERENT DEPTHS IN HORIZONTAL LAYERED MEDIA ON VARIATIONS OF SURFACE σs
Zhao Heyun Zhang Wenxiao Yang Mingzhi (Selsmological Bureau of Ningxia Hui Autonomous Region)
In this paper, based on the relation between the variations of ps at the surface above the nth horizontal layered media and the changes of electric properties in different depths, the concrete values of the depth-dependent variations of response coefficients (S(z)) in the second and third homogeneous horizontal media are computed, It is indicated that the magnitude of S(z) will represent the deteetability of quadripole symmetrical device in certain electrical structures. The results show that the depth-dependent variations of S(z) exhibitted a scoop-like form, with the maximum value ranging from one ninetieth AB to several-th AB. When the resistivity is high in the lower layer, the maximum value appears in the shallower depth, and when the resistivity is high in the lower layer, the maximum value appears in the deeper depth. The results also; demonstrates that the existence of large deviations in the electric properties between the upper and lower layers will be disadantageous to probing the variations of electric properties within deeper depths.