A new approach for calculating the apparent resistivity tensor  

作　　者：Zhou Cong Tang Jing-Tian Yuan Yuan Ren Zheng-Yong Li Yong 

机构地区：[1]State Key Laboratory of Nuclear Resources and Environment(East China University of Technology),Nanchang 330013,China [2]Key Laboratory of Geophysical Electromagnetic Probing Technologies of Ministry of Natural Resources of the People's Republic of China,Langfang 065000,China [3]Key Laboratory of Metallogenic Prediction of Nonferrous Metals,Ministry of Education,Central South University,Changsha 410083,China

出　　处：《Applied Geophysics》2021年第3期386-395,433,434,共12页应用地球物理（英文版）

摘　　要：The apparent resistivity tensor pB is an electromagnetic transfer function,which can be used to analyze and explain the underground electrical structure.Conventional method for obtaining the parameter requires controlled sources and can be easy to be disturbed by cultural noises.We present a new method for calculating the apparent resistivity tensor,the current density is first obtained by measuring the curl operator of the magnetic field on the Earth's surface.This approach is independent of the assumption of a plane wave,and may be used irrespective of source types and field areas.We derived the analytical expressions of the apparent resistivity tensor based on synthetic horizontally layered models with a vertical magnetic dipole source.We then calculate the responses of Pb through numerical modeling examples using both natural sources and controlled sources.Compared to traditional apparent resistivity definitions,our apparent resistivity tensor has the same amplitude value but with more sensitive phases in the far zone,and shows few distortions in the transition zone.And in the near-field zone,it is closer to the resistivity distribution under the ground.The simulation results have demonstrated the effectiveness of the proposed method for calculating the apparent resistivity tensor.

关 键 词：Apparent resistivity tensor curl of magnetic field CSAMT numerical modeling nonplanar wave 

分 类 号：P631.3[天文地球—地质矿产勘探]