Abstract
The left-lateral 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 spatial and
temporal distributions of shallow creep along the fault are not well
resolved. In this study, we obtain high-resolution interseismic velocity
maps along the 350-km-long central Xianshuihe Fault and Interferometric
Synthetic Aperture Radar (InSAR) timeseries along the Kangding segment
using ascending and descending Sentinel-1 data. The InSAR data reveal
multiple creeping sections and the estimated surface creep rates show
high along-strike variability. A coupling model characterizes the
distribution of creep with depth. The seismic potential of apparent
rupture asperities along the Xianshuihe Fault is further refined by
considering fault-crossing baseline data and the distribution of
historical ruptures and microseismicity. Moreover, a stress-driven
afterslip model of the observed accelerated creep around the Mw 5.9 2014
Kangding rupture indicates substantial shallow afterslip, which provides
further constraints on the distribution of locked and creeping patches
along this section of the Xianshuihe Fault.