磁偶极子构造法铁磁性物体干扰地磁观测正演  

Magnetic Dipole Reconstruction Method for Forward Modeling of Ferromagnetic Object Interference on Geomagnetic Observation

作　　者：郭宇鑫 张骞 张秀霞[2] 高熹微 李玉 GUO Yu-xin;ZHANG Qian;ZHANG Xiu-xia;GAO Xi-wei;LI Yu(Gaoyou Seismological Station,Jiangsu Province,Gaoyou 225600,China;Jiangsu Earthquake Agency,Nanjing 210014,China)

机构地区：[1]江苏省高邮地震台,江苏高邮225600 [2]江苏省地震局,南京210014

出　　处：《地震》2023年第2期145-155,共11页Earthquake

摘　　要：铁磁性物体是地磁观测中常见干扰源之一,选择合适的计算分析方法对其磁场进行准确正演具有重要的意义。为了快速求解铁磁性物体产生的干扰幅度及平面分布,本文提出了一种基于磁偶极子构造原理求解铁磁性物体磁场的数值计算方法,将物体分割为体积单元,每个单元视为“磁偶极子”,利用磁场叠加的方法计算得到了铁磁性物体在立体空间内的磁场分布特征。研究结果表明:铁磁性物体对地磁总场的干扰范围与背景磁场强度、体积及磁化率成正比,与其形状具有相关性;总场强度F、水平分量H、垂直分量Z以及磁偏角D所受干扰在三维空间内的分布与背景地磁场的方向相关。Ferromagnetic object is one of the common disturbance sources in geomagnetic observation,and it is of great significance to select a suitable calculation and analysis method for its accurate forward modeling of magnetic field.In order to quickly solve the amplitude and planar distribution of the interference generated by ferromagnetic objects,a numerical calculation method based on the principle of magnetic dipole structure is proposed to solve the magnetic field of ferromagnetic objects,in which the object is divided into volume units,with each unit regarded as a"magnetic dipole".The magnetic field distribution characteristics of ferromagnetic objects in three-dimensional space are calculated by using the method of magnetic field superposition.The results show that the interference range of ferromagnetic objects on the geomagnetic total field is proportional to the intensity,volume and susceptibility of the background magnetic field,and is related to its shape.The three-dimensional distribution of the interference on the total field intensity F,horizontal component H,vertical component Z and declination D is related to the direction of the background geomagnetic field.

关 键 词：铁磁性物体 地磁观测 磁偶极子 空间分布 

分 类 号：P318.6[天文地球—固体地球物理学]