MT法中静态效应及阻抗张量静态校正法

来源期刊：中南大学学报(自然科学版)2002年第1期

论文作者：杨生 鲍光淑 李爱勇

文章页码：8 - 13

关键词：静态效应;张量;电场畸变;静态校正;超相位;各向异性

Key words：static migration; tensor; electric field distortion; static correction; over phase; nonidentity

摘    要：大地电磁测深法(MT)中的静态效应使实测的视电阻率和相位曲线出现畸变,导致反演解释得出错误的结果.基于大地电磁测深响应在高频时具有一维响应特征,作者提出了对阻抗张量或实测的电场分量实施静态校正的方法,由高频的实测数据求取电场畸变张量和静态校正张量,而后对全频域的实测阻抗张量进行校正,以获得无静态干扰的张量.实践结果表明,通过校正静态效应,消除了静态效应对视电阻率和相位曲线产生的畸变现象.

Abstract: The static migration in magnetotelluric sounding(MT) affects the qualitative and quantitative interpretation.he authors discuss the effect law of static migration to MT ground response parameters. It indicates that even the electric field style static distortion also can change the form of appearance resistivity curve and phase curve. Phase curve even appears over phase. The static migration also affects electric major axes and two-dimensional diverge degrees. This made it difficult to respond to the geological meaning that it represented. It′s a very important step to make static migration correction in MT data processing. Or else we′ll obtain wrong inversion interpretation results. Based on the understanding that high frequency response of magenetotelluric sounding has one-dimensional response characteristics, the authors put forward a static correction method to impedance tensor or measured electric field component, which first extracts electric field distort tensor and static correction tensor from the high frequency measured data, then correct the measured impendance tensor in full frequency in order to obtain correct tensor component without static migration. It is an effective method in actual application. It can notonly reduce the distortion of appearance resistivity curve and phase curve affected by static migration, but also restore other magnetotelluric parameters data to normal.