SEISMOLOGY AND GEOLOGY ›› 1993, Vol. 15 ›› Issue (3): 247-252.

• Brief Report • Previous Articles     Next Articles

FORMATION MECHANISM OF MICROEARTHQUAKE SWARM IN YANGUAN AREA ON THE YANGTZE GORGES

Yang Qingyuan, Chen Xiancheng, Ma Wentao, Hu Yuliang, Hu Ping, Zhao Meng   

  1. Institute of Geology, SSB, Beijing 100029
  • Received:1991-12-31 Revised:1993-02-28 Online:1993-09-01 Published:2009-11-25

长江三峡地区盐关微地震群的成因机制

杨清源, 陈献程, 马文涛, 胡毓良, 胡平, 赵蒙   

  1. 国家地震局地质研究所, 北京100029

Abstract: The activity of microearthquake swarm is limited in an area of coal mine. There are two types of microearthquakes: one is the microearthquakes the first motion of which distributed in a quadrant belongs to double-couple sliding focal mechanism, with S wave energy higher than P wave energy. The other is the extreme-low microearthquakes, with P wave energy higher than S wave energy. The focal mechanisms are the nondouble-couple. Both they are coal-mine tremors, which can not be considered as an evidence for the northern extension of the Xiannushan fault.

Key words: Yangtze Gorges, Yanguan, Microearthquake swarm, Near-field observation, Coal-mine tremors

摘要: 盐关微地震群的活动局限在矿区内,地震都是微震和极微震。地震分两种类型:一种是微震活动,初动呈象限分布的双力偶滑动型震源机制,S波能量高于P波能量。另一种是极微震,初动几乎全负,P波能量高于S波能量,呈非双力偶的张破裂向内爆炸型的震源机制。两种地震的成因都是采矿诱发地震,不能做为仙女山断层向北延伸的证据。

关键词: 长江三峡, 盐关, 微震群, 近场观测, 矿山地震