2010年玉树7.3级地震前阿尔法导航信号场强异常分析  

Amplitude Anomalies of Alpha Signals before the 2010 Yushu M7.3 Earthquake

作　　者：赵庶凡[1] 张学民[1] 廖力[2] 钱庚[1] 

机构地区：[1]中国地震局地震预测研究所,北京100036 [2]中国地震局地球物理研究所,北京100081

出　　处：《地震》2016年第4期153-162,共10页Earthquake

基　　金：国家国际科技合作专项(2014DFR21280);亚太空间合作项目以及ISSI-BJ项目联合资助

摘　　要：利用俄罗斯三个阿尔法发射站与中国两个接收站雅安和通海之间形成的6条链路,获取阿尔法导航信号监测仪的场强数据,针对2010年4月14日青海玉树7.3级地震开展了震例分析研究。发现玉树地震前3天4月10日10:30左右,主台—雅安链路和主台—通海链路f1频率的场强都出现了显著的负异常,持续时间约为15分钟左右,同时两组异常序列呈现较高相关性,分析认为异常可能来源于同一个低电离层扰动。通过对当日所有链路的数据与背景数据对比分析,发现东、西副台与雅安、通海链路的f1频率场强均无异常变化,进一步表明这次低电离层扰动在主台-雅安和主台-通海2条链路的有效探测范围中。此外,f2频率和f3频率在全部6条观测链路上均无明显异常,说明低电离层扰动区在f2和f3频率的有效探测范围之外。这些结果的综合分析为扰动源方位判识提供了一定的科学依据。本文采用的方法可以作为未来分析阿尔法监测数据提取地震异常的一种有效方法。Amplitude data from six propagation paths formed by three Alpha transmitters in Russia and two Alpha navigation signal monitors in Ya＇an and Tonghai have been used to study the 2010 Yushu M7.3earthquake.It has been found that the f1 amplitude on the paths of Novosibirsk-Ya＇an and Novosibirsk-Tonghai has appeared prominently negative anomalies at about Beijing time 10：30,3days before Yushu earthquake which has lasting for about 15 minutes.High correlation of two anomalies on the two different paths may be caused by the same ionospheric disturbance.Comparing the data on April 14 with the background data,it has been found that the f1 amplitude on the paths of Krasnodar and Khabarovsk stations with Ya＇an and Tonghai have no disturbances,which further suggested that this perturbation of the lower ionosphere is located in the valid detection range of Novosibirsk-Ya＇an and Novosibirsk-Tonghai paths.In addition,there has been no significant anomaly at f2 and f3,which means the perturbation of the lower ionosphere is outside the detection range of f2 and f3frequency.Comprehensive analysis on these results could provide scientific basis for locating the disturbance of the lower ionosphere.The method adopted in this article can be used effectively in extracting seismic anomalies from Alpha monitor data in the future.

关 键 词：VLF电波 地震前兆 阿尔法导航信号 2010年玉树地震 

分 类 号：P315.7[天文地球—地震学]