磁化率异常体对大地电磁数据影响的规律研究  

The Influence of Magnetic Susceptibility Anomalies on Magnetotelluric Data

作　　者：朱德朋 王涛[2,3] ZHU De-peng;WANG Tao(China University of Geosciences,Beijing 100083,China;Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China;Key Laboratory of Electromagnetic Radiation and Sensing Technology,Institute of Electronics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]中国地质大学(北京),北京100083 [2]中国科学院空天信息研究院,北京100190 [3]中国科学院电磁辐射与探测技术重点实验室,北京100190

出　　处：《科学技术与工程》2020年第26期10573-10579,共7页Science Technology and Engineering

摘　　要：为探究地下介质的磁化率性质对大地电磁观测数据的影响,在常规大地电磁的正演过程中引入磁化率这一物性参数,利用有限单元法实现同时考虑电阻率和磁化率的二维大地电磁正演算法。在考虑野外噪声等因素的前提下,通过建立不同模型进行正演计算,详细分析磁性体的磁化率、背景电阻率、埋深等参数对大地电磁正演结果的影响,总结两种判定地下磁性体是否会对大地电磁数据产生影响的方法:若已知地下磁性体的规模,可根据磁性体的埋深与边长的比值系数判定;若未知地下磁性体的规模,可根据地磁测资料磁异常的幅值变化判定。To explore the influence of the magnetic susceptibility of underground medium on magnetotelluric observation data,the physical parameter of magnetotelluric susceptibility was introduced in the process of conventional magnetotelluric forward modeling.A finite element method was used to realize the two-dimensional magnetotelluric forward modeling algorithm that considers both resistivity and magnetization by using the.On the premise of field noise and other factors,the influence of magnetic susceptibility value,background resistivity value,buried depth and other parameters on magnetotelluric forward model was analyzed in detail by establishing different models for forward calculation.Finally,two methods were summarized to determine whether the underground magnetic body had an impact on magnetotelluric data.If the size of the underground magnetic body is known,it can be determined according to the ratio coefficient of the buried depth and the side length of the magnetic body.If the scale of underground magnetic body is unknown,it can be judged according to the amplitude change of magnetic anomaly in geomagnetic data.

关 键 词：大地电磁法 电阻率 磁化率 有限单元法 二维正演 

分 类 号：P319.11[天文地球—固体地球物理学]