Mechanism of the 2017 Mw 6.3 Pasni earthquake and its significance for future major earthquakes in the eastern Makran

On 7th February 2017, a moment magnitude (Mw) 6.3 earthquake rattled offshore Pasni in the eastern Makran and triggered a small tsunami. Using a combination of seismicity, multibeam bathymetry, seismic profile, InSAR measurements, and tide gauge observation, we conduct an in-depth investigation into the seismogenic structure, coseismic deformation, and tsunami characteristics of this event. Our results indicate that (1) the earthquake occurred on the shallow-dipping (3-4°) megathrust; (2) the megathrust co-seismically slipped 15 cm and caused ~2-4 cm ground subsidence and uplift at Pasni; (3) our tsunami modeling reproduces the observed 5-cm-high small tsunami waveforms. The Pasni earthquake rupture partially overlaps the 1851 and 1945 earthquake (M>8) slip patches, releasing estimated 3% and 7% of accumulative strain since then. With such stress perturbation, the Pasni earthquake could promote failure of megathrust in the future. This study calls for more preparedness in mitigating earthquake and associated hazards in the eastern Makran.