三峡水库水体荷载变化对地壳形变的影响  

Effect of Water Load Variation in the Three Gorge Reservoir on the Crustal Deformation

作　　者：孙伶俐[1,2] 姚运生[1,2] 蒋玲霞[1,2] 魏贵春[1,2] 王慧 罗俊秋[1,2] 

机构地区：[1]中国地震局地震研究所地震大地测量重点实验室,武汉430071 [2]湖北省地震局,武汉430071 [3]宜昌地震台,湖北宜昌443100

出　　处：《长江科学院院报》2015年第12期46-50,共5页Journal of Changjiang River Scientific Research Institute

基　　金：中国长江三峡集团公司科研专项(SXSN/3354;3511);中国地震局地震研究所所长基金(IS201546227;IS201226074);中国地震局三结合课题(22004041804-6);武汉市科技计划项目(2013060501010166)

摘　　要：为研究三峡水库水体荷载变化对地壳形变的影响,选取2001—2014年宜昌地震台的地壳形变潮汐与非潮汐参数进行分析,结果显示:原始数据分钟值、长趋势、潮汐因子、潮汐相位滞后等参数在三峡水库水体荷载变化过程中出现明显异常。地震前观测资料分钟值、长趋势出现异常:水管倾斜仪分钟值在秭归县屈原镇ML4.6级地震前4 h出现明显下降,N和S端下降量分别达23×10^(-3)角秒、10×10^(-3)角秒;洞体应变仪EW分量在巴东MS5.1地震前3月出现破年变转折,由压变张;潮汐分析结果显示异常:洞体应变NS分量潮汐因子在2001—2014年间出现阶段下降,2009年9月后,NS和EW分量潮汐因子发生同步异常变化(NS继续下降、EW小幅上升)。应变、倾斜的潮汐相位滞后在水位下降期和ML≥4.0级以上地震前均出现转向变化。In order to study the effect of water load variation in the Three Gorge reservoir on the crustal deformation,we used the observation data of crustal deformation of tidal analysis and none-tidal analysis at Yichang seismic station from 2001 to 2014,and there was clear evidence that original parameters such as the minute value,the long trend,tide factor and phase lag showed anomaly during the process of the variation of water load in the Three Georges reservoir. Anomalies of the minute value and the long trend data were observed before the earthquake; moreover,4 hours before the earthquake（ ML4. 6） in Quyuan town of Zigui county,the minute value of water tube tiltmeter declined significantly,and the amount of drop in north end and south end is up to 23 × 10^（-3）,10 × 10^（-3）angular seconds,respectively; at the time of 3 months before the earthquake（ MS5. 1） in Badong town,the EW component of hole strain gauge appeared to break the law of annual variation and changed from compression to tension; finally,tidal analysis results showed abnormal： the tidal factors of NS component of hole strain declined in phases from 2001 to2014,and the change of synchronous anomalies of the tidal factors of NS and EW components took place in September,2009,in other words,data of NS component continued to fall and data of EW component rose slightly; adverse change of the tide phase lag of strain and tilt appeared in the period of water level＇s drop and before earthquakes（ ML≥4. 0）.

关 键 词：地壳形变 宜昌地震台 三峡水库 水体荷载 震前异常 潮汐分析 

分 类 号：P315.725[天文地球—地震学]