摘要
根据水库蓄水后地震活动的时间分布特征,将水库诱发地震分为三个阶段,通过对三个阶段地震活动的震中分布、震源深度、震源机制解等活动特征进行分析,同时考证震中区历史上曾发生过的强烈有感地震,得出以下认识:①库区三个阶段地震动力成因各不相同,第一阶段主要是水库蓄水引发的初始应力释放,第二阶段地震动力来自东南方向,第三阶段地震动力来自西北方向。②水库诱发地震震中区历史上曾发生过强烈有感地震,震中区将成为区域构造应力场调整释放的"窗口",因此应加强水口库区的地震监测与防御。③在讨论福建地区地震动力成因时,不能只强调来自台湾岛弧碰撞对福建地区地震的控制作用,而忽略来自喜马拉雅碰撞带对福建地区的作用力。
According to the temporal distribution feature of seismicity after reservoir basin impoundment, this paper divides reservoir-induced earthquakes into three stages. Based on analysis on the seismicity characteristics of three stages which include epicentral distribution, focal depth, focal mechanism solution and investigation on the intense and sensible earthquakes that happened in history epicentral area, some conclusions are drawn ： 1） At the three stages, the origin of seismic dynamics in reservoir area differes from one another. The main cause of first stage is the original stress release initiated by reservoir filling; seismic dynamic of second stage is from southeast, and the third＇s is from northwest. 2） The reservoir-induced intense and sensible earthquake had been happened in history in the epicenter of seismicity area has ever happened. The epicenter will become an adjusting and releasing window for regional tectonic stress field, so it is needed to enhance seismic monitoring and defense of Shuikou （river outlet） reservoir. 3） When discussing the seismic dynamic origin in Fujian region, we can not only emphasize that Taiwan island arc collision has a constraining power to Fujian region, but ignored the applied force to Fujian region which is from Himalayan convergence belt.
出处
《华南地震》
2010年第3期53-62,共10页
South China Journal of Seismology
关键词
地震活动
地震成因
构造应力场
震源机制解
水口水库
Seismic dynamic origin
Seismicity
Focal mechanism solution
Tectonic stress field
Shuikou reservoir
