Investigation on seismic source activity and active geological hazards of the M_s 6.8 Dingri earthquake in Tibet

On January 7， 2025， a M_s 6.8 earthquake struck Dingri County in Shigatse， Tibet， resulting in significant casualties and extensive damage. This work employs synthetic aperture radar differential interferometry， optical remote sensing， and field surveys to investigate the surface deformation and seismogenic geological hazards. A novel procession algorithm for Lutan-1 registration and interferometry is suggested to meet the urgent time requirements of emergency rescue. It is revealed that the earthquake caused significant surface displacement， with the main coseismic deformation zone covering up to 12281 km². Deformation was concentrated near the Dengmocuo fault， with a maximum line-of-sight displacement of up to 2 m. Based on deformation characteristics and high-resolution optical images， a total of 219 active geological hazards were identified. The seismic movement induced or facilitated the deformation of these active hazards. In addition， the spatial distribution of these hazards was controlled by seismic intensity and also by the characteristics of topography， geomorphology， road networks， and river systems. Moreover， three typical active landslides along crucial roads were specifically highlighted to illuminate the post-seismic fragile geological environment around them. These three active landslides pose serious threats to the safe operation of nearby national or county roads and power facilities. Close attention should be paid to them during the emergency rescue period and post-disaster reconstruction period. These findings provide scientific references for the prevention and control of geological hazards related to seismic sources and for post-disaster reconstruction planning.