摘要
利用150例水库诱发地震震例和532个国内大型水库资料,使用灰色聚类方法,按库深、库容、区域应力状态、断层活动性、岩性介质条件和地震活动背景等6个诱震因素,统计出相应的发震比例数,以此作为水库地震预测指标。再根据长江三峡水库坝址区、香溪河口及仙女山断裂带过江段、泄滩西和巴东及神龙溪两岸的6个独立的诱震因素,评估各段的水库诱发地震震级上限。计算结果表明长江三峡水库坝址区震级上限<3级,香溪河口及仙女山断裂带过江段4~5级,泄滩西<3级,巴东北岸及神龙溪两岸震级3~4级。并得到了长江三峡水库蓄水后实际地震情况的验证。
In this paper,a statistical analysis is made using the gray clustering method on the earthquake inducing factors, such as dam height, storage capacity, regional stress state, fault activity, lithology medium conditions and seismic activity background, based on a database of reservoir-induced earthquakes,which includes 150 reservoir-induced earthquake cases and 532 large reservoirs data. Corresponding earthquake occurrence ratios are obtained and used as predictors for reservoir-induced earthquakes. According to the six quake-inducing factors, assessment is made on the maximum magnitude of reservoir-induced earthquake for the Three Gorges Reservoir dam area, the bayou of Xiangxi stream and the cross-river section of the Xiannushan Fault zone,the west Xietan, Badong,and on both banks of Shenlong stream. The results show that the upper-limit of magnitude at dam area is less than magnitude 3,that at the bayou of Xiangxi stream and the cross-river section of Xiannushan Fault zone is between magnitude 4 - 5 ,that at west of Xietan is less than magnitude 3, and that at the northern bank of badong and on both banks of the Shenlong stream is between magnitude 3 - 4. The results have been validated by the actual reservoir-induced seismicity after the impoundment of the Three Gorges Reservoir, with the ML 2 earthquake at Xiaoxikou 4 km far away from the dam of the Three Gorges Reservoir on February 6, 2009, the Ms 4. 1 earthquake at the bayou of Xiangxi stream and the cross river section of the Xiannushan Fault zone on November 22,2008, the Ms 2.6 earthquake at the west Xietan on August 22, 2009, and the ME 3. 5 earthquake at the bank of Shenlong stream on December 14,2009.
出处
《地震地质》
EI
CSCD
北大核心
2012年第4期726-738,共13页
Seismology and Geology
基金
"十一五"国家科技支撑计划项目(2008BAC38B04)资助
关键词
灰色聚类方法
震级上限
评估
水库诱发地震
长江三峡水库
gray clustering method, the upper limit of magnitude, assessment, reservoir-inducedearthquake, the Three Gorges Reservoir