山西代县M_(S)3.0地震地磁异常与构造的关系  

Relationship between Geomagnetic Anomaly and the Geologic Structure of Daixian M_(S)3.0 Earthquake in Shanxi Province

作　　者：刘德强 苏树朋[2] 赵慧琴[2] 昝书林 LIU Deqiang;SU Shupeng;ZHAO Huiqin;ZAN Shulin(Hebei Hongshan National Observatory on Thick Sediments and Seismic Hazards,Xingtai 05400,China;Mobile Survey Team of Hebei Earthquake Agency,Baoding 071000,China)

机构地区：[1]河北红山巨厚沉积与地震灾害国家野外科学观测研究站,河北邢台054000 [2]河北省地震局流动测量队,河北保定071000

出　　处：《华北地震科学》2023年第1期66-68,74,共4页North China Earthquake Sciences

基　　金：河北地震科技星火计划项目(DZ2021121600010,DZ2021121400007,DZ2021121600003)。

摘　　要：2019年9月13日山西代县发生M_(S)3.0地震,通过对震区及周边2期流动地磁总强度观测数据进行处理,得到2019年4—8月岩石圈磁场总强度变化特征,发现震中刚好位于零值线上;震中东侧出现NE向展布的显著负异常区,和发震断层走向一致,沿此断裂分布的测点异常能量较强,同时震区外围靠近断裂的测点也出现了较明显的异常,说明外围构造存在应力状态改变的现象,晋北局部地区应力场背景复杂,异常幅值与测点至断裂的距离具有较好的相关性。Daixian M_(S)3.0 earthquake occurred on September 13,2019 in Shanxi Province.By processing two phases observation data of mobile geomagnetic total intensity in and around the earthquake area,we obtained the variation model of total magnetic field intensity of lithosphere from April to August 2019.It is found that the epicenter is just on the zero line.On the east side of the epicenter,there is a local significant negative anomaly area distributed in NE direction,which is consistent with the strike of the seismogenic fault.The abnormal energy of the measuring points distributed along the fault is strong,and obvious anomalies also appear at the measuring points near the fault in the periphery of the earthquake area,which shows that the peripheral structure also has the phenomenon of stress state change.There may be a background of high stress field in some areas of northern Shanxi.The abnormal amplitude has a good correlation with the distance from the measuring point to the fault.

关 键 词：代县M_(S)3.0地震 岩石圈磁场 震磁异常 构造相关性 

分 类 号：P315.72[天文地球—地震学]