摘要
2002年3月3日大桥水库诱发了Ms4 6级地震,根据大桥台网7年多库区地震观测记录,在2001年9～11月库区内有密集分布的高频次近地表的小震群活动,以致库区内地震存在b值与η值等地震学参数异常。这个小震群震级小、频次高,分布在一个震源深度浅地域小的空间范围内。小震群的震中分布与安宁河东支断裂和库水位有关。借用基于GIS的地震分析预报系统对天然构造活动引起的震群分析方法和指标,对该小震群进行分析后认为:小震群为典型的前兆震群。
An M4.6 induced earthquake occurred near Daqiao Reservoir Dam. According to the seismic events recorded for 7 years by the seismic network of Daqiao, there were a lot of concentrated small earthquakes near the surface of the crust around the area of the reservoir from September to November 2001. These small earthquakes groups result in the presentation of the abnormal indexes such as b-value and η-value parameters used in the seismology researches. The distribution of these small seismic events is mainly along the eastern sub-fault of Anninghe Faults. The seismicity is statistically relative to the level of water of the reservoir. Basing on our study, we point out that these small earthquakes are one kind of precursory earthquakes.
出处
《四川地震》
2004年第2期36-41,共6页
Earthquake Research in Sichuan
关键词
大桥水库
诱发地震
小震群
Daqiao Reservoir
induced earthquake
small earthquake group
