基于D—InSAR的九寨沟地震同震形变场反演分析

利用覆盖九寨沟地区的RadarSat—2数据与Sentinel—1A数据,采用精轨数据进行定轨,消除轨道误差,并结合合成孔径差分(D-InSAR)方法中的双轨差分技术,获取2017年8月8日Mw7. 0级地震的同震形变场。结果表明,视线方向(LOS)最大沉降量约为20 cm,隆起量达9 cm。基于弹性半空间形变模型反演该地震的断层滑动分布,得出该地震断层滑动以左旋走滑为主,走向为330°,倾角为32°,滑动角为-170°,同震滑动分布主要集中在4～12 km深度处,最大滑动量位于9 km处,约为6. 14 m,平均滑动量为0. 57 m。反演获得的地震标量矩为4. 06E+18N·m,震级Mw约为6. 4,深度为19. 5 km。

Inversion analysis of co-seismic deformation field of Jiuzhaigou earthquake based on D-InSAR

On the basis of RadarSat-2 data and Sentinel-1A data covering the Jiuzhaigou area, the August 8, 2017 co-seismic deformation field of the Mw 7.0 Earthquake is acquired by determining orbit using precision orbit data, eliminating orbital errors and combining the Dual-track difference technique in the synthetic aperture difference (D-InSAR) method. The results show that the maximum subside of the line of sight (LOS) is about 20 cm and the amount of upraise is 9 cm. Based on the elastic half-space deformation model, the fault slip distribution of the earthquake was inverted and the slip of the fault was dominated by left-lateral strike-slip, with a strike of 330°, an inclination of 32°, a sliding angle of -170°. The co-seismic slip distribution focused on the depth of 4~12 km, with the maximum sliding amount of 6.14 m located at the depth of 9km, and the average sliding amount of 0.57 m. The seismic scalar moment obtained by inversion is 4.06E+18N·m, the magnitude Mw is about 6.4, and the depth is 19.5 km.