石油地球物理勘探2023，Vol.58Issue(6)：1489-1498,10.DOI:10.13810/j.cnki.issn.1000-7210.2023.06.021
大地电磁电场远参考道法适用条件及应用效果
Applicable conditions and effects of remote reference method of magnetotelluric electric field
摘要
Abstract
The remote reference method is effective for processing magnetotelluric(MT)time series data.It is generally believed that magnetic fields yield better effects as reference channels,but electric fields are not suitable as remote reference channels due to their susceptibility to underground structures.Based on actual data processing,this paper explores the utilization of electric fields as reference channels for processing MT data and finds that they per-form well in the high-frequency range above 1 Hz but poorly in the low-frequency range.Then,it puts forward a new approach that employs electric fields as reference channels for processing high-frequency data.Fine processing of audio magnetotelluric(AMT)data confirms the validity of electric fields as reference channels in the high-fre-quency range(＞1 Hz).Application of this approach to AMT data processing indicates that the results obtained by adopting electric fields as reference channels are comparable to those by utilizing magnetic fields as reference chan-nels,with sound improvement in data processing of AMT"dead band"(1k～5k Hz).AMT data collection typically involves multiple measurement points sharing a set of magnetic channels,and the electric channel number greatly ex-ceeds that of magnetic channels.Thus,processing of remote reference channel electric fields can significantly im-prove AMT data processing results and can be popularized as a conventional processing method.Analysis of natural source electromagnetic fields and MT dimensionality parameters shows that the limited influence of high-frequency electric fields on underground structures is the underlying reason for the remote reference channel data effectiveness of electric fields.This research also provides guidance for the location selection of remote reference stations,suggest-ing that the stations should be situated in areas with simple geoelectric structures to minimize interference of under-ground electrical structures on natural electromagnetic field signals from the same source as the survey area.关键词
大地电磁/远参考道法/电场/音频大地电磁/阻抗张量Key words
magnetotelluric/remote reference method/electric field/audio magnetotelluric/impedance tensor分类
天文与地球科学引用本文复制引用
王培杰,陈小斌,张赟昀,杨静,董泽义..大地电磁电场远参考道法适用条件及应用效果[J].石油地球物理勘探,2023,58(6):1489-1498,10.基金项目
本项研究受应国家自然科学基金地震联合基金项目"地震、重力与大地电磁联合反演算法研究及在川滇地区岩石圈结构高分辨率成像的应用"(U1839205)和应急管理部国家自然灾害防治研究院基本科研业务专项"川滇菱形地块北部电性结构探测研究"(ZDJ2019-26)联合资助. （U1839205）
