摘要
用姚安地震序列前震、主震和余震的 78个震源机制解 ,分析了序列震源断层和震源应力场特征。结果表明 ,姚安地震序列的主破裂面是走向N5 0°W、倾角陡立的构造断裂 ,主震、前震和绝大多数余震都发生在主破裂面上。此外 ,NNE NE向构造断裂在序列发展过程中也参与了活动。序列震源应力场以SSE方位、接近水平的主压应力为主 ,与区域构造应力场一致。在序列发展中 ,震源区应力场出现多方位和多作用方式共存的复杂状态 。
We use 78 focal mechanisms of the fore shocks, main-shock and after shocks of the Yao'an earthquake sequence to analyze the characteristics of focal fault and stress field. The results show that the strike of main fracture plane is N50°W and the dip is sharp. The fore shocks, main-shock and most of after shocks occurred on the main fracture plane. The focal stress field is oriented as SSE, nearing horizontal compressive stress field and consistent with tectonic stress field in this area. It presents that the occurrence of the main-shock is the result that tectonic stress field goes salient buildup. The dislocation properties of the main fracture are right-lateral strike-slip under the action of stress field possessed of the direction SSE, nearing horizontal. The focal region stress field represents complex status with multi-azimuth and multi-action mode. The focal rupture appears complex feature with multi-direction and multi-representation forms.
出处
《中国地震》
CSCD
北大核心
2002年第1期59-66,共8页
Earthquake Research in China
基金
云南省重点科技攻关项目<云南强震中短期预测研究>(2 0 0 1NG46 )课题资助
