Increased far-field landslide hazards due to postseismic acceleration by the 2017 Mw 6.4 Nyingchi earthquake

• The 2017 Mw 6.4 Nyingchi earthquake increased landslide hazards in the far field. • Landslide activity remains high even five years after the earthquake. • Rainfall and aftershocks both influence the postseismic landslide dynamics. Landslides represent a major type of earthquake-triggered geohazard, with their dynamic evolution influenced by the complex interaction of postseismic environmental factors. The 2017 Mw 6.4 Nyingchi earthquake triggered numerous landslides, yet research has largely focused on coseismic mapping, and there remains a lack of cataloging and characterization of postseismic landslides accelerated by the earthquake (i.e., Earthquake Accelerated Landslides, EALs). These landslides remain a serious hazard to surrounding communities, with impacts that persist well beyond the earthquake. This study employs Sentinel-1 time-series analysis to reveal the spatial distribution and postseismic deformation mechanisms of EALs. A total of 299 EALs were identified and cataloged, which are primarily distributed in high mountainous regions west of the epicenter and show a distinct linear clustering along active faults. By comparing near-field and far-field EALs, we found that far-field landslides may experience greater acceleration despite weaker ground shaking. Time-series analysis indicated a rise in EAL deformation velocity from 1.56 cm/yr (preseismic) to 5.08 cm/yr (postseismic), reflecting a strong accelerating effect of the earthquake. In addition to the deformation acceleration triggered by the mainshock, postseismic landslide deformation also exhibited seasonality correlated to precipitation and land surface temperature, as well as aftershock-induced variations. Exponential modeling further indicates a decreasing deformation trend of EALs, with stabilization occurring approximately 6.8 years after the mainshock. This research systematically examined landslide evolution after the Nyingchi earthquake, providing a basis for post-earthquake landslide hazard assessment, with particular emphasis on the increased far-field landslide hazards.