2015—2016年大华北地区岩石圈磁场变化及震前异常特征*
赵慧琴,云 萌,苏树朋,张海洋,李 博,张纳莉

(河北省地震局 保定中心台,河北 保定 071000)

大华北地区; 地磁矢量观测; 岩石圈磁场; 磁异常特征

Lithospheric Magnetic Field Variation and Pre-seismic Anomaly Characteristics in North China Area from 2015 to 2016
ZHAO Huiqin,YUN Meng,SU Shupeng,ZHANG Haiyang,LI Bo,ZHANG Nali

(Baoding Central Seismic Station of Hebei Earthquake Agency,Baoding 071000,Hebei,China)

North China; geomagnetism vector observation; lithosphere magnetic field; magnetic anomaly characteristics

备注

利用2015—2016年大华北地区260个测点流动地磁矢量资料,结合河北尚义4.0级和唐山4.0级地震,对获得的相邻期岩石圈磁场变化进行了分析。结果 表明:尚义4.0级地震震中附近水平矢量H方向出现转向,同时处于磁偏角D变化的零值线上,磁倾角I和总强度F变化无明显的局部异常特征。唐山4.0级地震震中位于水平矢量H量级由北至南出现突然减小的变化,同时处于磁偏角D负值高梯级带边缘,也位于磁倾角I变化的正负值交界处,而总强度F却无明显的局部异常特征。

Using the mobile geomagnetism vectors of 260 observation points in North China from 2015 to 2016,and combing with the M4.0 earthquake in Shangyi,Hebei as well as M4.0 earthquake in Tangshan,we analyzes the accessibly adjacent lithospheric magnetic field variation.The results indicate that the horizontal vector H changed direction near the M4.0 earthquake of Shangyi,and it is on the zero value line of the variation of the magnetic declination D,while the variation of magnetic inclination I and the total intensity F have no evident local anomaly features.The M4.0 earthquake epicenter in Tangshan is located in the horizontal vector H,where a variation of sudden diminution in it's magnitude from south to north; meanwhile,it is on the edge of high gradient zone of magnetic declination D's negative value,and is also located at the junction of positive and negative values of magnetic inclination I's variation.However,the total intensity F has no evident local anomaly features.