2022年青海门源M_(W)6.6地震InSAR三维同震形变估计及断层滑动分布反演

Estimation of Three-Dimensional Coseismic Deformation and Inversion of Fault Slip Distribution for the Menyuan,Qinghai M_(W)6.6 Earthquake in 2022 Using InSAR

采用覆盖门源地区的C波段Sentinel-1卫星与L波段ALOS-2卫星遥感数据,运用差分干涉(D-InSAR)、像素偏移量追踪(POT)以及多孔径InSAR(MAI)技术,获取2022年青海门源M_(W)6.6地震同震视线向和方位向地表形变场。结合地表应力应变模型与方差分量估计(SM-VCE)方法,推导出地震三维同震位移。采用非线性和线性方法反演断层倾角、走向等几何参数和同震滑动分布特征。结果表明,该地震为左旋走滑型地震,断层自震中向北西-南东方向延伸,最大水平位移达1.58 m,且主要滑动集中在地下0~8 km范围内,最大滑动量为3.54 m,反演的矩震级为M_(W)6.67。

We use remote sensing data from the C-band Sentinel-1 and L-band ALOS-2 satellites,which cover the Menyuan area,and apply differential interferometry(D-InSAR),pixel offset tracking(POT),and multi-aperture InSAR(MAI)techniques to obtain the coseismic surface deformation fields of the 2022 Menyuan,Qinghai M_(W)6.6 earthquake in line-of-sight and azimuth directions.By combining the surface stress-strain model with the variance component estimation(SM-VCE)method,we deduce the three-dimensional coseismic displacement.Furthermore,we use both nonlinear and linear approaches to invert the geometric parameters,such as dip angle and strike,as well as the distribution characteristics of coseismic slip.The results reveal that the earthquake was a left-lateral strike-slip event,with the fault extending northwest-southeast from the epicenter.The maximum horizontal displacement reached 1.58 m,and the predominant sliding occurred within a depth range of 0 to 8 km underground,with a maximum slip of 3.54 m.Based on the inversion results,the moment magnitude of earthquake is estimated to be M_(W)6.67.