2015年尼泊尔8.1级地震前后拉萨地电场观测数据变化分析  

Geo-electric Field Changes Observed at Lhasa Geomagnetic Station before and after the 2015 Nepal M8.1 Earthquake

作　　者：席继楼[1] 关华平[1] 刘超[1] 庄楠[1] 杨晓明[1] 张治国 次卓嘎 格桑卓玛 马爱明 

机构地区：[1]中国地震局地震预测研究所(地震预测重点实验室),北京100036 [2]西藏自治区地震局,西藏拉萨850000 [3]北京陆洋科技开发公司,北京100036

出　　处：《地震》2016年第2期1-13,共13页Earthquake

基　　金：中国地震局地震预测研究所基本科研业务专项重点项目(2013IES0101、2014IES0101)资助

摘　　要：2015年4月25日尼泊尔8.1级强烈地震前后,拉萨地磁台(以下简称"拉萨台")地电场观测数据出现了长时间、大幅度异常变化。在对拉萨台地电场观测条件、观测系统以及观测结果进行初步讨论的基础上,利用"能量合成累加"和"MSA功率谱分析"等数据处理方法,从"时间域"和"频率域"两个方面,对该异常变化的主要特征和演化过程进行了分析。结果显示,尼泊尔8.1级地震前后,拉萨台的地电场观测数据异常变化,经历了"趋势变化-扰动变化-发震期-恢复期"等发展阶段,以及"低频变化-高频变化-平稳变化-高频变化"等演化过程。综合分析认为,拉萨台地电场观测异常变化特征和演化过程,与相关现象和机理研究结果基本吻合,能够完整反映强烈地震孕育、发生和发展全过程,是具有一定客观性、典型性和代表性的珍贵资料。The main purpose of this paper is to analyze the characteristics of the geo-electric field observations,with the long time span and the large amplitude abnormal changing,in the Lhasa geomagnetic station before and after the Nepal M8.1strong earthquake,occurred in April 25 th,2015.The observation condition,the observation system,and the observation data of the Lhasa station have been preliminary discussed firstly,and then the main characteristics of the abnormal change and evolution process are analyzed and studied,using＂the synthesis energy accumulative＂and＂the power as MSA spectrum analysis＂methods,from two aspects of time domain and frequency domain.The results show that the abnormal changing of the geo-electric field observation of the Lhasa station experiences development stage of＂trend change-disturbance change-earthquake period-recovery period＂,and evolution process of low frequency change-high frequency change-stationary changehigh frequency change＂,before and after the Nepal M8.1strong earthquake.Comprehensive analysis shows that the characteristics and evolution process of the geo-electric field observations of the Lhasa station are basically consistent with the relevant mechanism.It is the valuable data,with certain objectivity,typical and representative,to reflect the whole process of the breeding,occurrence and development of such strong earthquake.

关 键 词：地电场变化 尼泊尔8.1级地震 拉萨地磁台 能量合成累加 MSA功率谱 

分 类 号：P315.7[天文地球—地震学]