Coseismic Fault Slip and Transtensional Stress Field in the Hovsgol
Basin Revealed by the 2021 Mw 6.7 Turt, Mongolia Earthquake
Abstract
Knowledge of the regional crustal deformation and stress field is
fundamental to understanding and constrain the ongoing Hovsgol basin
evolution. The 2021 Mw 6.7 Turt earthquake provides an unprecedented
opportunity to probe the local tectonic stress field and upper crust
deformation. We investigate the coseismic surface displacements and
invert fault slip models using Interferometric Synthetic Aperture Radar
observations and teleseismic data. The mainshock occurred as a result of
normal faulting with a right-lateral strike-slip component on an NW
striking plane, which is consistent with the transtensive local stress
field inverted from regional focal mechanisms. Our results also suggest
that the current deformation of the Hovsgol basin is dominated by
half-graben forming. The 1950 Mondy earthquake may advance the 2021 Turt
earthquake by ~7% recurrence interval, meanwhile, the
2021 Turt earthquake may increase the potential seismic hazard on the
neighbor Mondy and South Hovsgol Fault, which deserves more attention.