Estimation of coseismic deformation and a fault model of the 2010 Yushu earthquake using PALSAR interferometry data

We present a map of the coseismic displacement field and slip distributions resulting from the Yushu earthquake on 14 April 2010 in Qinghai, China. The wide coverage of ScanSAR data helps in increasing the opportunity of interferometric synthetic aperture radar (InSAR) observations of a specific location on Earth, estimating surface slip, and constraining slip distribution on the fault plane. We increased InSAR sensitivity to the horizontal and vertical surface displacements by combining ascending and descending interferograms. We find that the maximum left-lateral surface slip is 166 cm at ~ 9.7 km WNW of Yushu. The end-to-end length of surface and subsurface faults is about 73 km, and the estimated lengths of the two surface fault lines are 30 km and ~ 9 km. Slip distribution on a fault plane inverted from InSAR data shows an almost pure left-lateral strike-slip, with two slip peaks near the epicentres and Yushu and a maximum slip of ~ 2.6 m. No postseismic deformation is observed southeast of the source region; however, we detected a significant postseismic displacement northwest of the source region. The deformation area is located a few kilometres northwest of the coseismic displacement area observed around Longbao Lake, suggesting that the coseismic slip and the postseismic slips are spatially isolated.

Research highlights
► ScanSAR interferogram helped to analyse deformation of the 2010 Yushu earthquake.
► Estimated surface left-lateral strike-slip faulting is over 100 cm around Yushu.
► The total length of ruptured faults is about 73 km.
► Slip distribution on the fault plane has two slip peaks.
► Detected a significant postseismic displacement NW of the source region.