铁磁性物质对地磁观测影响的野外测试  

Field Test of the Influence of Ferromagnetic Materials on Geomagnetic Observation

作　　者：康健[1] 孙嘉良 张明东[1] 胡培元[1] 龚永俭[1] 陈志刚[1] KANG Jian;SUN Jialiang;ZHANG Mingdong;HU Peiyuan;GONG Yongjian;CHEN Zhigang(Tianjin Earthquake Agency,Tianjin 300201,China)

机构地区：[1]天津市地震局,天津300201

出　　处：《华北地震科学》2022年第3期55-61,共7页North China Earthquake Sciences

基　　金：中国地震局地震监测、预报、科研三结合“地磁环境干扰影响野外测试研究”(CEA-JC/3JH-202001003);天津市地震局项目“铁磁性物质对地磁观测环境的影响及分析”(Zd202105)。

摘　　要：通过野外测试方法,使用G856T质子旋进磁力仪对不同质量铁磁性物质在野外选定点位逐一测量,并使用GM4磁通门磁力仪对相同质量铁磁性物质在野外不同方向各点位测试对地磁场水平东西向D、水平南北向H和垂直向Z的干扰;结合天津区域地磁台站近年来受铁磁性物质干扰的典型实例,研究铁磁性物质对地磁观测的影响。结果表明:①铁磁性物质对地磁观测干扰幅度的实测结果与理论计算值接近,偏差与试验场地地下介质磁性不均匀和铁磁性物质的材料、形状、体积等有关;②铁磁性物质质量越大对地磁观测的影响范围越广,靠近铁磁性物质的磁场梯度大,等值线变密,反之亦然;③铁磁性物质对地磁场D、H和Z的干扰幅度及形态在方向上有一定的规律,可作为判定铁磁性干扰源方位的依据。Through the field test method,G856T proton precession magnetometer is used to measure ferromagnetic substances of different mass at selected points in the field,and ferromagnetic substances of the same mass are placed at points in different directions in the field.GM4 fluxgate magnetometer is used to measure their interference with geomagnetic fields D,H and Z,combined with the typical examples of ferromagnetic substances interference in Tianjin regional geomagnetic station in recent years,the influence of ferromagnetic materials on geomagnetic observation is studied.The results show that:①The measured results of the interference of ferromagnetic materials on geomagnetic observation are close to the theoretical calculated values in amplitude,and the deviation may be related to the magnetic inhomogeneity of underground media in the test site and the material,shape and volume of ferromagnetic materials.②The greater the mass of ferromagnetic material,the wider the influence range of geomagnetic observation.The magnetic field gradient near ferromagnetic material is large,and the isoline becomes dense,and vice versa.③The interference amplitude and form of ferromagnetic substances on geomagnetic fields D,H and Z have certain rules in direction,which can be used as the basis for judging the orientation of ferromagnetic interference sources.

关 键 词：地磁场 铁磁性物质 干扰形态 幅度 方位 

分 类 号：P315.7[天文地球—地震学]