武都水库地震活动监测及分析  

Monitoring and analysis of the seismic activity in the Wudu reservoir

作　　者：王翠芳[1] 徐辉 黎阳 庄园旭 胥珍 杜瑶[1] WANG Cuifang;XU Hui;LI Yang;ZHUANG Yuanxu;XU Zhen;DU Yao(Sichuan Earthquake Agency,Chengdu 610041,China;Wudu Diversion Water Construction Administration,Mianyang City,Sichuan Province,Sichuan Province 621000,China)

机构地区：[1]四川省地震局,中国成都610041 [2]四川省绵阳武都引水工程建设管理局,中国四川621000

出　　处：《地震地磁观测与研究》2022年第5期33-39,共7页Seismological and Geomagnetic Observation and Research

基　　金：中国地震局监测、预报、科研三结合课题(课题编号:3JH-202002020)。

摘　　要：武都水库是高坝大型水库(设防烈度Ⅶ度),库区地处龙门山断裂带的主中央断裂与主边界断裂之间,并位于2008年汶川M_(S) 8.0地震的破裂带内。本文选取2014年2月1日—2018年12月31日武都水库监测区记录的4142次地震进行时空分析,厘清地震的空间分布特征、大坝周围分布特征和时间进程分布特征,并对库区及周边14次M_(L)≥3.0地震对水库大坝的影响进行分析,得出以下结论:①武都水库监测区地震分布特征:2014—2018年,监测区共发生M_(L)≥3.0地震7次;地震活动集中分布在水库库尾和坝前,形成2个明显的丛集区;地震主要沿SW—NE和NW—SE两个垂直剖面分布,震源深度均小于20 km;在大坝NW偏N方向约3—40 km处,地震活动频次较高;监测区内地震活动水平整体较低,地震日频次仅2.89;②在研究时段内,监测区及周边M_(L)≥3.0地震对水库大坝的影响有限,但仍需密切关注地震活动,以保障人民的生产、生活和生命安全。The Wudu reservoir is a large reservoir with a high dam(located in the earthquake intensity Ⅶ area).The whole reservoir is located between the main central fault and the main boundary fault of the Longmen mountain fault zone,also located in the rupture zone of the 2008 Wenchuan M_(S) 8.0 earthquake.This paper selected 4142 earthquakes recorded in the Wudu reservoir monitoring area from Feb.1,2014,to Dec.31,2018,to carry out a spatial-temporal analysis to clarify the spatial distribution characteristics of the earthquakes,the distribution characteristics around the dam,and the distribution characteristics along time.The impacts of 14 M_(L)≥3.0 earthquakes in and around the reservoir on the reservoir dam were also analyzed.It is concluded that①A total of 4142 earthquakes were recorded within the monitoring area,including 7 M_(L)≥3.0 and earthquakes.The seismic activities of the Wudu reservoir are concentrated at the end of the reservoir and in front of the reservoir dam,forming two obvious cluster areas.The earthquakes are mainly distributed on two perpendicular profiles in the SW-NE and NW-SE directions,with depths of less than 20 km.High seismic activity is observed 3-40 km away from the dam in the north-northwest direction.The seismic activity level in the monitoring area is relatively low with a daily seismic frequency of only 2.89.This paper also describes the impacts of 14 typical M_(L)≥3.0 earthquakes on the reservoir and the dam.②During the study period,the impacts of M_(L)≥3.0 earthquakes on the reservoir dam were limited;however,seismic activity still needs to be closely watched to ensure the safety of the people’s production and life.

关 键 词：武都水库地震监测 地震活动空间分布 大坝周围地震分布特征 地震活动时间分布 

分 类 号：TV697.24[水利工程—水利水电工程]