高频大地电磁测深法静态效应校正研究

地表存在不均匀体,往往会对高频大地电磁测深资料产生静态影响,造成出现虚假的垂向大延伸异常体现象,严重影响资料解释结果。本文对不同情况下静态效应影响采用有限元法进行了正演模拟及分析,得到了静态影响的规律。提出了利用浅地表的岩性电阻率参数去标定电阻率曲线的首支后,再进行小尺度空间滤波来压制静态影响的校正方法。经过我国西部某河道深厚覆盖层勘探中的实际应用,表明这种方法是比较理想的校正方法。

The Study of Static Effects and Correction in High Frequency Magnetotelluric Method

There are several shallow inhomogeneous bodies on the earth surface, which in- variably has a static influence on the data of high--frequency magnetotelluric sounding method, causes mendacious phenomenon of anomalous body extending vertically, and im- pacts seriously on data interpretation results. This paper made forward modeling and ana- lyzed static effects under different conditions by finite element method, and obtained the rule of static effects. This paper also put forward a correction method of suppressing the static effects by small scale space filter after standardizing the first branch of the resistivity curve by the shallow or surface lithologic resistivity data. The practical application in deep overburden layer exploration in certain river of west of China proves that this method is a fairly ideal for static correction.