水平地层上的负激发极化效应及其物理解释

本文首先阐明负激电效应是客观存在的;然后用等效电阻率法导出地面上点源供电时的二次极化电位、电场强度、电流密度的表达式,并依此用线性滤波法对各种给定参数进行计算,依此对二次极化场的分布规律进行物理分析,对激电负效应给出直观的物理解释;最后,根据土槽模拟实验资料,证实了负激电效应的客观存在,反演数据也与实际情况相吻合。本文还得到二极装置和错层条件下的负激发极化效应。

THE NEGATIVE IP EFFECT AND ITS PHYSICAL INTERPRETATION FOR HORIZONTAL LAYERS

In this four-part paper first, the so-callec "paradox" negative IP effect and the studies on it by other geophysicists are introduced. Then, on the bases of equivalent resistivity method, the formulas for the potential, field intensity, and current density of the secondary pollariza-tion field are developed and used to calculate the anomaly for given parameters by means of linear filter method. Various maps are plotted from the calculation. Using these maps, we analyze the distribution of secondary polarization field from the viewpoint of physics and present a direct, and physical explanation. Thus the mystery of negative IP effect is solved. Finally, the objectiveness of such effect is proven by the data from soil-tank experiment conducted by us. Furthermore, the quantitative interpretation data by inverse calculation agree with the actual parameters. On the other hand, we have the negative IP effect on two electrode array and over mixed layers.