2000年1月15日姚安6.5级地震余震序列震源机制解与震源区应力场分析

本文利用垂直向的Pg和Sg波的最大振幅比方法,计算2000年1月15日云南姚安6.5级地震后余震序列震源机制解,通过统计和系统聚类分析,再结合震中分布图,综合分析了云南姚安6.5级地震的震源机制解和震源区应力场破裂特征,研究结果表明震源断层的走向为SEE-NWW占主导,其平均解为120°,震区主压应力轴平均解为145°,即SSE向,与震源区现今构造应力场主压应力方向一致,表明余震的应力场主要受区域应力场的控制.

Focal Mechanism and Stress Field of Aftershock Sequence in the Source Area of January 15, 2000 Yao＇an M 6.5Earthquake

Using the vertical Pg and Sg wave maximum amplitude ratio calculation, the calculation of focal mechanism solution of aftershoek sequence in January 15, 2000 Yao Yunnan 6. 5 earthquake, by statistical method and system blustering analysis method, combined with the epicenter distribution map, the authors analyzed the focal mechanism of Yunnan Yao＇ an M 6. 5 earthquake and the source area stress field characteristics. Research results show that the focal fault to SEE NWW dominates, the average solution is 120 DEG, earthquake compressive principal stress axes average solution is 145 DEG, in SSE direction; and the principal compression stress field direction is consistent with tectonic seismic zone, showing that the aftershoek stress field is affected by the regional stress field.