Partial coupling and earthquake potential along the Xianshuihe Fault, China

Surface creep rate variation along the XSF (a) A map view (N47°E) of the XSF fault geometry from NW to SE along strike. (b) Creep rate variation along the XSF. Surface creep rate measurements from Zhang et al. (2018) are shown with yellow stars. (c) Spatial-temporal distribution of the most recent historical earthquake ruptures along the XSF.

Project Summary The Xianshuihe Fault is located at the eastern boundary of the Tibetan Plateau and is one of the most active faults in China. It is associated with substantial seismic potential, with more than 20 Mw>6 earthquakes since 1700. The fault has been documented to be creeping at the surface for decades; however, the details of the distribution of creep in space and time are not well resolved. In this study, we use more than 3 years of Sentinel-1 InSAR data from ascending and descending orbits to retrieve the subtle interseismic deformation signal in the Xianshuihe Fault region. We identified two ~25-km-long creeping segments indicated by a sharp velocity gradient across the fault collocated with recent earthquake ruptures. The results indicate high spatial variability of surface creep rate ranging from 0~5 mm/yr.

Tools InSAR, GPS, fault-crossing baseline

Geographic Location Tibetan Plateau, China

Group Members Involved Yuexin Li <Email> <Personal Web Site> Roland Bürgmann

Project Duration 2018 - 2020

Reference Li & Bürgmann, in prep, 2020