Present-Day Crustal Deformation and Seismic Hazard of the Sichuan-Tibet Transportation Corridor Constrained by InSAR and GPS

ABSTRACT The Sichuan-Tibet Transportation Corridor (STTC) is a major strategic infrastructure project currently under planning and construction in China, traversing multiple active faults with a history of frequent seismic activity. It is imperative to assess fault activity and seismic hazard along the STTC. This study integrated Interferometric Synthetic Aperture Radar and Global Positioning System to derive high-resolution 3D deformation fields along the corridor. The results show that significant deformation is concentrated along the Xianshuihe fault and the eastern Himalayan syntaxis, whereas being distributed diffusely elsewhere. The Xianshuihe and Litang faults exhibit left-lateral shear, with slip rates of 10.2 ± 0.9 and 0.6 ± 0.5 mm/yr, respectively. Other faults in the region are predominantly right-lateral shear, among which the Jinshajiang fault shows a relatively higher slip rate of 2.5 ± 0.5 mm/yr, whereas the remaining faults have similar rates of ∼1 mm/yr. The differential movement between blocks results in varying degrees of activity along the major faults, which accommodate much of the strain across the STTC. A synthesis of seismic moment balance and distribution of earthquakes suggests a relatively low seismic risk for the Zheduotang section of the Xianshuihe fault. The central sections of the Jiali fault and Dedeng fault exhibit notable seismic potential. The central sections of the Lancangjiang fault and Jinshajiang fault have seismic moment deficits, suggesting the possibility of future moment magnitude (Mw) 6.4 and 6.5 earthquakes, respectively. This research has implications for understanding the deformation pattern of the Tibetan Plateau and for seismic fortification of major infrastructure projects, including the STTC.