Differential motions of the Gozha Co Fault (Xizang) before and after the 2008 Yutian earthquake revealed by ENVISAT-1 ASAR

Shallow fault creep is a relatively rare phenomenon, often indicating a lower seismic risk (less strain accumulation). Previous studies have revealed shallow creep on the Gozha Co Fault in the western Qinghai-Xizang Plateau using Sentinel-1 and ALOS-2 data, but its formation mechanism remains unclear. Considering the 2008 M_S7.3 Yutian earthquake that occurred to its north, which may have influenced the fault's movement, we used time series interferometry to process descending ENVISAT-1 SAR data from 2003 to 2010. This allowed us to obtain the line-of-sight deformation field before and after the 2008 Yutian earthquake. The results show that the Gozha Co Fault did not exhibit significant differential motion before the 2008 Yutian earthquake, while the fault moved left-laterally after the event. Therefore, we propose that the shallow creep on the Gozha Co Fault may have been triggered by the 2008 M_S7.3 Yutian earthquake. This work is helpful for analyzing the physical mechanisms of fault shallow creep and earthquake potential in the western Qinghai-Xizang Plateau.