摘要
瓦屋山水电站位于川西台陷南端，南邻峨眉山断块，水库南缘的毛沟断裂最新活动时期为晚更新世，水库处于活动性大地构造环境中。该区属于名山—马边—昭通地震带北段，以弱震活动为主，伴有少量中强地震，目前正处于地震活动期。从分析库区地质构造、水文地质、工程地质、地震活动等条件，并使用水库综合影响系数法、贝叶斯概率预测法，断层强度分析法，判定库区存在着发生构造型水库诱发地震的可能性，诱发地震强度Ｍｓ≤５．５。划分了两个水库诱发地震危险区：①黄店子—张沟Ｍｓ＝５左右危险区；②穆沟—王村Ｍｓ≤４．０危险区。
Wawushan hydroelectric station is situated at the southern tip of depressed block in western Sichuan and its south is closed to the Emeishan fault block.Along the southern margin of reservoir, there is a failure,named Maogou failure. The last active Period of this failure is Epileistocene.The area of reservoir is being an unstable state of tectonic structure.This area belongs to the northern portion of Mingshan-Mabian-Zhaodong seismic zone. Its primary activities are weak earthquakes, occasionally accompanied by a few of moderately strong earthquakes.Presently, it is being a high active Period.Analysing the conditions of geologic structure, hydrologic geology, engineering geology and seismic activity, using methods of synthetic influencing factors, Bayesian probability prediction and fracture intensity analysis, it can be determined that there exists the occuring probability of a tectonic earthquake of Ms≤5.5 induced by the reservoir in this area. Then we delineate two earthquake danger areas:①Huangdianzi-Zhanggou, with Ms=5;②Mugou-Wangchun, with Ms<4.0.
出处
《地震地磁观测与研究》
1996年第2期35-43,共9页
Seismological and Geomagnetic Observation and Research
关键词
地震
水库地震
诱发地震
危险性
工程地震
seismic belt, reservoir earthquake, faulting activity, hydrographic stratifiedsection, danger area
