2016年门源地震震源机制DInSAR同震形变反演  

Coseismicdeformation focal mechanisms inversion for 2016 Menyuan earthquake by DInSAR observations

作　　者：张明 高涵[2] 牛玉芬[3] 曲菲霏[3] 万虹麟 张薇 

机构地区：[1]云南省基础测绘技术中心,昆明650034 [2]云南省地震局,昆明650225 [3]长安大学,西安710065 [4]河北水利电力学院,沧州061001

出　　处：《地球物理学进展》2017年第3期1089-1094,共6页Progress in Geophysics

摘　　要：确定地震的发震要素,理解断裂带断层的活动性质及地震震源机制,对于潜在性的地震灾害分析预报工作具有重要意义.2016年1月21日门源地震发生后,众多学者对于该次地震的发震要素、震源机制为纯逆冲还是走滑兼逆冲等仍存在争议,因此本文利用两景Sentinel-1A影像,经D-In SAR技术处理得到2016年青海门源MW5.9地震的同震形变位移,通过两步法位错反演模型分析确定了门源地震的主要影响区域及断层的滑动分布,为其他广大科研人员的进一步深入研究提供参考.同震位移图显示此次地震造成了明显的地表形变,其中冷龙岭南侧距门源县城较远区域产生了LOS向最大同震抬升约为8 cm的近椭圆形变区域.反演结果显示门源地震发震断层为深度7.9 km、走向约130°、倾角约46°、滑动角约47°、断层最大滑动为约0.6 m的左旋逆冲断层.地震过程中,断层滑动分布标量地震矩约为1.02×10^(18)Nm,对应矩震级约为MW5.9.Understanding the earthquake elements,the dynamic characteristics of the fault zone and the seismic source mechanism which have great significance to essential for the potential seismic hazard analysis and forecasting work. After the earthquake occurred on January 21 2016,many scholars are still controversial for the earthquake elements and mechanism which should be pure thrust or strike slip simultaneously with thrust,therefore,in this paper,we obtain the co-seismic deformation displacements of Qinghai Menyuan MW5. 9 earthquake using two Sentinel-1A images which processing by DInSAR technology, after it a two-step dislocation inversion method was used to model and identify the affected areas of main earthquake source and analysis fault slip distribution,provide a reference for other scientific researcher to study further. The coseismic displacement figure shows the earthquake caused significant surface deformation,the south side of Lenglongling region where far away from the Menyuan county reach the largest uplift LOS displacement of about 8 cm, the earthquake had no significant settlement near elliptical deformation zone area. The optimal fault geometric parameters of 2016 Qinghai Menyuan MW5. 9 Earthquake shows that the seismogenic fault was a left-lateral fault with depth 7.9 km,striking angle 130°,dip angle 46°,slide angle 47°,the maximum slip of about 0. 6 m. During the earthquake,the accumulative seismic moment was up to about 1. 02 × 10^18 Nm,equivalent to a magnitude of MW5. 9.

关 键 词：门源地震 构造活动 位错反演 D-In SAR 

分 类 号：P315[天文地球—地震学]