丹江口水库诱发地震研究

丹江口水库由汉江、丹江两个库段组成。在丹库的峡谷灰岩地带 ,断裂、节理发育 ,利于水的渗透和循环。 196 7年 11月蓄水后 ,随水位的增加 ,地震活动增加 ,且震级由Ms<2 .5上升到Ms =4.7,并在丹库的峡谷附近形成北北西方向延伸的 3个地震密集区。地震频度、强度与水位 (库容 )变化有一定的相关性。预测二期工程蓄水后 ,仍将产生诱发地震 ,其最大强度为Ms≤ 5 .0。

RESEARCH OF INDUCED EARTHQUAKE AT DANJIANGKOU RESERVOIR

The Danjiangkou Reservoir is composed of two parts, the Dan River and Han River Reservoirs. In the gorge district of the Dan River Reservoir(the limestone area) faults and joints are well-developed and they are favourable to the permeation and circulation of water.After impounding in November 1967, the seismicity has increased with the rise of water level. The earthquake magnitude in the past years rose from %M%s<2.5 to %M%s4.7 and three earthquake clustering areas, spreading in the NNW direction formed near the gorge district of the Dan River Reservoir.The frequency and intensity of the earthquakes are correlated with the change of water level in the reservoirs.It is estimated that after impounding in the second engineering stage the reservoir induced earthquake will occur again,and maximum magnitude may reach %M%s5.0.