2009年云南姚安6.0级地震震源机制与发震构造的分析研究
|
摘要
利用P波、SV波、SH波初动及其振幅比联合反演震源机制解的方法,计算了2009年7月9日发生在云南姚安6.0级地震余震序列的震源机制解,同时结合地震序列的空间分布,对姚安6.0级地震的发震断层性质和震区应力场特征进行综合分析。结果分析表明:(1)姚安6.0级地震发震断层为NWW—SEE向的直立右旋走滑断层,与美国哈佛大学的主震CMT解节面基本一致,也与余震优势方向分布一致,证明结果可靠;(2)震区主压应力场优势方向为NNW—SSE向,与其现今区域构造应力场主压应力NNW—SSE向一致,表明主震应力场主要受到现今区域构造应力场的控制,同时还有一些小的余震与主震应力场不同,表明震区应力场的多样性和复杂性;(3)结合本次地震序列的空间分布、震源机制解特征、震区断裂构造特征综合分析,综合判定姚安6.0级地震的发震构造属于马尾箐断裂。
Using joint inversion method with amplitude ratio of P wave、SV wave and SH wave,this paper calculated focal mechanism of aftershock sequence of Yaoan earthquake with MS6.0.According to the space distribution of earthquake sequence,the author analyzed the characteristics of stress field and seismogenic fault.The result showed that:(1) seismogenic fault of Yaoan earthquake was a vertical right-lateral strike-slip fault,striking NWW—SEE.The result was reliable,also consistent with nodal plane of CMT result offered by Harvard and predominant direction of aftershocks;(2) predominant direction of principal compressive stress in NWW—SEE was consistent with regional tectonic stress,and some aftershocks were different from main shock.Stress field of main shock was controlled by regional tectonic stress,indicated diversity and complexity in seismic area;(3) analyzing the distribution of earthquake sequence、focal mechanism and fault structure in seismic area comprehensively,seismogenic structure of Yaoan earthquake belongs to Mawei-jing fault.
Using joint inversion method with amplitude ratio of P wave、SV wave and SH wave,this paper calculated focal mechanism of aftershock sequence of Yaoan earthquake with MS6.0.According to the space distribution of earthquake sequence,the author analyzed the characteristics of stress field and seismogenic fault.The result showed that:(1) seismogenic fault of Yaoan earthquake was a vertical right-lateral strike-slip fault,striking NWW—SEE.The result was reliable,also consistent with nodal plane of CMT result offered by Harvard and predominant direction of aftershocks;(2) predominant direction of principal compressive stress in NWW—SEE was consistent with regional tectonic stress,and some aftershocks were different from main shock.Stress field of main shock was controlled by regional tectonic stress,indicated diversity and complexity in seismic area;(3) analyzing the distribution of earthquake sequence、focal mechanism and fault structure in seismic area comprehensively,seismogenic structure of Yaoan earthquake belongs to Mawei-jing fault.
引文
[1]梁尚鸿,李幼铭,束沛镒.利用区域地震台网P、S波振幅比测定小震震源参数[J].地球物理学报,1984,27(3):249-256.
[2]刘杰,郑斯华,康英.利用P波和S波的初动和振幅比计算中小地震的震源机制解[J].地震,2004,24(1):20-26.
[3]赵小艳,苏有锦,付虹,等.用P波、S波初动和振幅比计算中小地震震源机制在云南地区的应用[J].内陆地震,2009,23(3):395-402.
[4]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代活动特征的探讨[J].地球物理学报,1977,20(2):96-109.
[5]张宏志,刁桂苓,陈棋福,等.1976年唐山7.8级地震震源区现今地震震源机制解分析[J].地震研究,2008,31(1):1-5.
[6]皇甫岗,秦嘉政,李忠华,等.云南地震活动性[M].昆明:云南科技出版社,2010.
[7]李玉江,陈连旺,李红,等.云南地区构造应力应变场变化特征的数值模拟[J].大地测量与地球动力学,2009,29(2):13-19.
[8]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代活动特征的探讨[J].地球物理学报,1977,20(2):96-109.
[9]申重阳,吴云,王琪.云南地区主要断层运动模型的GPS数据反演[J].大地测量与地球动力学,2002,22(3):46-51.
[10]张建国,刘丽芳,李西,等.大姚、姚安强震区地震构造初析[J].地震地质,2009,31(3):536-543.
[2]刘杰,郑斯华,康英.利用P波和S波的初动和振幅比计算中小地震的震源机制解[J].地震,2004,24(1):20-26.
[3]赵小艳,苏有锦,付虹,等.用P波、S波初动和振幅比计算中小地震震源机制在云南地区的应用[J].内陆地震,2009,23(3):395-402.
[4]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代活动特征的探讨[J].地球物理学报,1977,20(2):96-109.
[5]张宏志,刁桂苓,陈棋福,等.1976年唐山7.8级地震震源区现今地震震源机制解分析[J].地震研究,2008,31(1):1-5.
[6]皇甫岗,秦嘉政,李忠华,等.云南地震活动性[M].昆明:云南科技出版社,2010.
[7]李玉江,陈连旺,李红,等.云南地区构造应力应变场变化特征的数值模拟[J].大地测量与地球动力学,2009,29(2):13-19.
[8]阚荣举,张四昌,晏凤桐,等.我国西南地区现代构造应力场与现代活动特征的探讨[J].地球物理学报,1977,20(2):96-109.
[9]申重阳,吴云,王琪.云南地区主要断层运动模型的GPS数据反演[J].大地测量与地球动力学,2002,22(3):46-51.
[10]张建国,刘丽芳,李西,等.大姚、姚安强震区地震构造初析[J].地震地质,2009,31(3):536-543.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心