地震灾害是人类面临的重大考验,阿尔法导航系统在地震预报领域有着重要的科研及应用价值。以2010年4月13日23时49分(世界时)玉树MS 7.1地震为例,基于2010年4月6日—13日阿尔法导航系统超低频(VLF)电波场强和相位数据,使用滑动四分位法,分析该系统9条链路上的信号异常,结合地磁“低点位移”现象,综合分析此次地震前的异常变化。研究结果表明:在地磁活动平静时段,玉树MS 7.1震前3天及震前23 h,电波场强数据出现明显畸变,表现为持续1—6 h超阈值的异常扰动,最大扰动幅度超过阈值13.6 μV/m,相位数据未出现明显异常。结合震前3天阿尔法导航系统主台—通海台、西副台—雅安台异常链路以及震前47天地磁“低点位移”分界线的重叠位置,可进一步精确临震预报时刻,并提高发震位置的预测精度。
Earthquake disaster is a major test for human beings all the time and the Alpha Navigation System plays an important role in scientific research and application value of earthquake prediction.Taking the Yushu MS 7.1 earthquake as an example,based on the field strength and phase of the VLF radio wave from April 6 to 13,2010,the signal anomalies on 9 links of the system are analyzed by using the sliding inter quartile range method,and the abnormal changes before the earthquake are comprehensively analyzed in combination with the geomagnetic low-point displacement.The results indicate that there is an obvious distortion in field strength 3 days before and 23 hours before the earthquake respectively during the quiet period of geomagnetic activities.The abnormal disturbance exceeds the threshold for 1-6 hours and the maximum amplitude of disturbance exceeds the threshold by 13.6 μV/m,but the phase reflects no anomaly.Combined with the overlap among the two anomalies links 3 days before the earthquake and the boundary of geomagnetic low-point displacement 47 days before the earthquake,the prediction accuracy of time and location of impending earthquake prediction can be further improved.
2022,43(3): 102-108 收稿日期:2021-9-16
DOI:10.3969/j.issn.1003-3246.2022.03.015
基金项目:中国地震局地震研究所和中国地震局地壳应力研究所基本科研业务费专项
作者简介:钱庚,硕士,工程师,主要从事地震监测及电磁数据处理。E-mail:qiangeng121@163.com
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