利用GPS资料分析新疆两次6级地震震前位移微动态特征  

MICRODYNAMIC CHARACTERISTICS OF DISPLACEMENT BEFORE TWO M6 EARTHQUAKES IN XINJIANG AREA USING GPS DATA

作　　者：李思妍 李桂荣[1] 王晓飞 阿卜杜塔伊尔·亚森[1] LI Si-yan;LI Gui-rong;WANG Xiao-fei;Abudutayier Yasen(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2024年第3期231-241,共11页Inland Earthquake

基　　金：新疆地震科学基金(202211,202215);新疆地质灾害防治重点实验室开放基金(XKLGP2022K01,XJLGP2022K02)。

摘　　要：以新疆地区GPS连续观测站的站点坐标三分量时间序列为数据源,通过希尔伯特黄变换(简称HHT)特定滤波频段捕捉新疆两次6级地震震前中短期地表位移微动态异常变化信息。以2017年8月9日精河MS6.6地震为例,获取HHT滤波频段3.8580×10^(-7)~6.4300×10^(-8)Hz(周期30~180天),能够在发震前40天提取到短期前兆异常及孕震信息。使用该频段对2016年11月25日新疆阿克陶MS6.7地震分析,震前55天左右,震中附近两两相关站点的振幅、幅值相干函数值和相关系数出现明显高于背景水平的位移微动态变化。两次地震事件表明,能够从一年时间尺度内的GPS连续观测资料中提取到有价值的震前位移微动态特征及地震孕育信息,为地震趋势研判提供参考依据。Using the time series of GPS continuous observation stations in Xinjiang as the data source,Hilbert Yellow transform(HHT)was used to capture the microdynamic anomaly changes of ground surface displacement in the short and medium term before the M6 or above earthquake in Xinjiang.Taking the M S6.6 Jinghe earthquake on August 9,2017 in the North Tianshan Seismic belt as an example,through the source mechanism solution,baseline time series and HHT single time series analysis,the HHT filter frequency band is 3.8580×10^(-7)~6.4300×10^(-8)Hz(period 30-180 days).Some short-term precursor anomalies and seismogenic information were extracted 40 days before the earthquake.Using this frequency band,the Aketao M S6.7 earthquake on November 25,2016 in Xinjiang was analyzed.About 55 days before the earthquake,the amplitude,amplitude coherence function value and correlation coefficient of the two related stations near the epicenter showed micro-dynamic changes of displacement significantly higher than the background level.Two seismic events show that it is possible to extract valuable micro-dynamic characteristics of pre-seismic displacement and earthquake preparation information from GPS continuous observation data in a one-year time scale,which provides a reference for earthquake trend analysis.

关 键 词：GPS 希尔伯特黄变换 位移微动态 时间序列 

分 类 号：P315.7[天文地球—地震学]