基于地磁重复观测资料的大同盆地及邻区地磁场研究  

The Research of Geomagnetic Field in the Datong Basin and Its Adjacent Region Based on Repeat Geomagnetic Measurement Data

作　　者：宋成科[1] SONG Chengke(The First Monitoring and Application Center,China Earthquake Administration,Tianjin 300180,China)

机构地区：[1]中国地震局第一监测中心,天津300180

出　　处：《防灾科技学院学报》2025年第1期68-77,共10页Journal of Institute of Disaster Prevention

基　　金：2025年度震情跟踪任务(CEA-ZQGZ-202501067);煤炭智能开采与岩层控制全国重点实验室开放基金(SKLIS202420)。

摘　　要：基于2019—2024年地磁场总强度重复观测结果,使用泰勒多项式方法建立了2019.0~2024.0年代大同盆地及邻区地磁主磁场模型和地磁场长期变化模型。结果表明,大同盆地及邻区地磁主磁场变化均匀,变化范围约为54500~56000 nT,长期变化呈现线性变化,年变率约为30~35 nT。2019.0~2024.0年代地磁场长期变化结果与呼和浩特地磁台记录的地磁场长期变化一致,但比国际地磁参考场模型结果小约1/3,说明区域地磁场模型能够更准确地描述区域地磁场的特征。岩石圈磁场分析表明,基于地面地磁观测资料的岩石圈磁场模型基本能够反映区域岩石圈磁场特征,与地磁场异常网格(EMAG)对比结果表明基于地磁观测的岩石圈磁场模型量值较大,反映了测点局部和浅部的地磁异常,但空间分辨率较EMAG低,这主要受地磁测点空间密度影响。Basing on the repeat measurement data of the geomagnetic total intensity from 2019 to 2024,we established the main magnetic field model and the geomagnetic secular variation model in the Datong Basin and its adjacent region from 2019.0 to 2024.0 epochs by the Taylor polynomial method.The results show that the variation of main magnetic field in the study area is uniform,ranging from 54500 to 56000 nT,with a linear secular variation and an annual rate of 30-35 nT.The secular variation of the geomagnetic field from 2019.0 to 2024.0 epochs is consistent with that of the Hohhot geomagnetic observatory,but is about one-third smaller than that of the international geomagnetic reference field model,indicating that the regional geomagnetic field model can more accurately describe the regional geomagnetic field.Analysis results of the lithospheric magnetic field show that the lithospheric magnetic field model is constructed based on ground geomagnetic observation data can basically reflect the characteristics of the regional lithospheric magnetic field.Comparison with the Earth Magnetic Anomaly Grid(EMAG)model,it is found that that the geomagnetic values of the lithospheric magnetic field model based on ground geomagnetic observation are larger,which reveals the local and lower crust magnetic anomaly.However,the spatial resolution of EMAG is higher,whose is mainly affected by the spatial density of geomagnetic measurement stations.

关 键 词：主磁场 岩石圈磁场 长期变化 地磁重复观测 泰勒多项式 

分 类 号：P318.5[天文地球—固体地球物理学]