[关键词]
[摘要]
采用基于近远震波形的CAPjoint 方法,对2013 年3 月27 日台湾南投MW6. 0 地震分别进行了单独反演和联合反演,获得了各自的震源机制解及震源深度。其中,联合反演所得的最优双力偶机制解参数为,节面Ⅰ:方位角0°,倾角30°,滑动角78°;节面Ⅱ:方位角193°,倾角60°,滑动角96°;震源深度18km。为了验证联合反演的有效性和可靠性,采用由重抽样理论发展而来的Bootstrap 方法,对近远震数据分别进行了重采样,并对其单独反演和联合反演所得的参数进行了统计,验证了联合反演的有效性及稳定性,并发现远震反演震源深度的结果一定程度上受台站分布的影响,若要获得精确的震源深度则需要方位角分布较好的远震台站记录。根据前人对集集地震及车笼埔断层的研究成果以及南投地震的发震断层性质接近车笼埔断层的认识,推测此次地震可能发生在车笼埔断层上。
[Key word]
[Abstract]
We used the CAPjoint method in inverting point source parameters of the 2013 Nantou earthquake,which includes both local and teleseismic waveforms. The result shows that the best double-couple solution of the event is 0°,30°,78° for strike,dip and rake,respectively. The other nodel plane is 193°,60°,96°,and the centroid depth is 18km. We applied Bootstrap method for statistics and verified that joint inversion is effective for constraining source parameters of moderate earthquakes. And we found that the centroid depth from inversion of teleseismic waveforms is depended on the azimuthal coverage of the teleseismic stations. The similarity between the focal mechanism and focal depth of the Nantou earthquake,and the characteristics of the Chelungpu fault imply that the Nantou event might rupture on the Chelungpu fault.
[中图分类号]
[基金项目]
地震公益性行业科研专项( 201308013 )、国家自然科学基金( 41174086 )、中科院测地所重要方向项目(KZZD-EW-TZ-05)联合资助