福建古田水口库区M_L4.8震群分析与水库诱发地震探讨

Discussion on Shuikou Reservoir M_L4.8 Earthquake in Gatian,Fujian Province and Reservoir-induced Earthquake

阐述了水口库区及邻近地区的地震地质构造特征和库区蓄水前后的地震活动变化特点。重点分析了水库蓄水以来发生的最大地震——古田ML4.8地震序列,并对库区地质与水文环境条件、诱发地震成因、机理等进行了研究。结果表明:水口库区地震与水库蓄水有直接关系,诱发地震震中主要集中在古田县水口镇湾口—前洋一带,范围约13km2。库区地震活动还将持续较长时间,且库区水位的升降与地震之间的相关性将越来越弱。最后对水口库区地震预测方法和最大震级进行了阐述。

We expatiate the geological structure of Shuikou reservoir and its vicinage and the seismicity fore-and-aft sluice. We analyze Gutian ML4. 8 earthquake, the maximum earthquake occurred in Shuikou reservoir area, then analyze the geological structure and the hydrological environment of Shuikou reservoir and the mechanism of res- ervoir-induced earthquake. The result shows that the earthquakes occurred in Shuikou reservoir are correlated with sluiced, and most epicenters concentrated in Wankou-Qianyang zone, Shuikou Town, Gutian County. The area is about 13 square kilometers. The activity of earthquake of Shuikou reservoir will keep long time, and the correlation between the rise and fall of water line of Shuikou reservoir and the occurrence of earthquake. Finally we discuss the method of forecasting the reservoir-induced earthquake and the maximal class earthquake of Shuikou reservoir.