去学水电站流动地震监测台网建设及蓄水初期地震活动初步分析-华南地震

文章信息/Info

Title:: Preliminary Analysis of Quxue Hydropower Station Flow Seismic Monitoring Network Construction and Early Period Impounding Seismic Activity

Author(s):: DU Yao; WANG Yuxi; RUAN Xiang; ZHAO Yu; WU Tong; GE SANG Zhuoma; Sichuan Earthquake Agency，Chengdu 610041，China

Keywords:: Quxue Seismic Monitoring Network; Monitoring Ability; Earthquake Cluster; Minimum Integrity Magnitude

摘要:: 四川去学水电站位于四川省甘孜藏族自治州得荣县境内，金沙江二级支流硕曲河干流上，库区及附近处于青藏高原东南缘地质结构不稳定地区，地震构造背景复杂。介绍了该水库地震监测台网及监测能力情况，并利用记录的蓄水后近10个月地震数据，对库区及附近的地震活动时空特征进行了初步分析。分析认为水库监测区域内地震主要集中分布在两个区域，一个位于在大坝及以东且延硕曲河展布，另一个则是大坝以南28～30 km处，沿德钦—中甸—大具断裂分布；利用最小完整性震级ML 0.3级以上地震分区进行了时间进程分析，两个区域地震活动强度均较弱，但频度和深度上有明显的差异，表明大坝附近地震活动水平在时间趋势变化上受水库蓄水有一定影响，需加强跟踪监测库区及附近地震活动。

Abstract:: Sichuan Quxue Hydropower Station is located in Derong County，Ganzi Tibetan Autonomous Prefecture，Sichuan Province，the main stream of the Shuo River in the second tributary of the Jinsha River. Its reservoir area is located in geological structure unstable area of southeast Tibetan Plateau，with complex seismic structure background. This paper introduces this reservoir’s seismic monitoring network construction and monitoring ability，and preliminarily analyzes the earthquake time and space characteristics by using earthquake statistics of 10 months after impounding. The analysis has shown that the earthquake in reservoir area mainly distributes in two areas：one is located in the east of the dam and spread along Shuoqu River；the other one is in the 28-30 km the south of the dam, and is distributed along Deqin- Zhongdian- Daju. Using earthquake zone with minimum integrity magnitude ML≥0.3, the paper conducts time progress analysis. The earthquake activity intensities in both areas are relatively weak, but there is obvious difference in frequency and depth. It shows that the earthquake level around the reservoir is influenced by reservoir storage in time tendency, and it is necessary to strengthen tracing and monitoring reservoir and earthquake activities around.