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Partial coupling and earthquake potential along the Xianshuihe Fault, China
  • Yuexin Li,
  • Roland Bürgmann
Yuexin Li
University of California, Berkeley

Corresponding Author:[email protected]

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Roland Bürgmann
University of California, Berkeley
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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.
Jul 2021Published in Journal of Geophysical Research: Solid Earth volume 126 issue 7. 10.1029/2020JB021406