华北区域性地磁低点位移异常特征
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摘要
利用河北及邻省共 1 7个台站的地磁 Z分量资料 ,统计分析了地磁低点位移的异常特征。研究结果表明 :1异常并不与静、扰日存在明显的依赖关系 ;2异常具有季节性变化 ,冬、夏季最多 ,秋季次之 ,春季最少 ;3异常偏离中午的最大时间大多在下午及偏西方位 ;4有震异常占总异常 35% ,异常后 1个月内发震的占有震异常 47%。并认为一次较强地震前 ,日变低点位移可能有多次异常出现 ,利用文中提出的地磁交汇法进行追踪预报效果较好。
The characteristics of geomagnetic low-value displacement anomalies statistically analyzed by using the geomagnetic Zcomponent data from Hebei and neighboring provinces′ 1 7observation stations. The study results show that:1 The anomalies do nothave obviously dependentrelations with calm ornoisy day. 2 Anomalies have seasonal changes—itchanges mostin winter and summer,the second in autumn,and the less in spring. 3 The maximum time thatanomalies deviate from noon is mostly in the afternoon and in the west direction. 4 Anomalies corresponding to earthquakes are3 5% of the total anomalies,and the anomalies thatan earthquake occurs in a month are4 7% of them. The low-value displacementanomalies in daily changes may appear many times,and we can get good prediction effect using the method of geomagnetic convergence presented in this paper.
The characteristics of geomagnetic low-value displacement anomalies statistically analyzed by using the geomagnetic Zcomponent data from Hebei and neighboring provinces′ 1 7observation stations. The study results show that:1 The anomalies do nothave obviously dependentrelations with calm ornoisy day. 2 Anomalies have seasonal changes—itchanges mostin winter and summer,the second in autumn,and the less in spring. 3 The maximum time thatanomalies deviate from noon is mostly in the afternoon and in the west direction. 4 Anomalies corresponding to earthquakes are3 5% of the total anomalies,and the anomalies thatan earthquake occurs in a month are4 7% of them. The low-value displacementanomalies in daily changes may appear many times,and we can get good prediction effect using the method of geomagnetic convergence presented in this paper.
引文
[1 ] 解用明 ,韩宝善 .磁暴与华北地区地震活动的关系 [J].西北地震学报 ,1 997,1 9( 1 ) :47- 52 .
[2 ] 解用明 .张北 6.2级地震前后的地磁 Z分量的日变化 [J].华北地震科学 ,1 998,1 6( 3) :64- 65
[2 ] 解用明 .张北 6.2级地震前后的地磁 Z分量的日变化 [J].华北地震科学 ,1 998,1 6( 3) :64- 65
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