The 14 December 2021, Mw 7.4 Flores Earthquake: Review of the hypocenter relocation, slip distribution, coulomb stress, and seismic hazard

A major earthquakes struck the north of Flores island, in Nusa Tenggara Timur, Indonesia, on 14  December 2021 at 10:20:22 local time, the hypocenter is 7.59°S, 122.26°E, depth 12.0 km, with moment magnitude Mw 7.4. The faulting orientation of the mainshock, fault plane was strike = 290°, dip = 89°, and rake = 177°, and the auxiliary plane was strike = 21°, dip = 87°, and rake = 1°, respectively, is possibly related to thrust fault in the sea. Focal mechanism solutions for the earthquakes indicate rupture occurred thrust fault with large dip angle. The mainshock was followed by low aftershocks productivity may due to homogeneous faulting systems and relatively uniform stress state in that region. We analyze aftershock hypocenter relocation and gravity anomaly, slip distribution, coulomb stress and seismic hazard (PSHA) to investigate the earthquake characteristics and seismic hazard analysis. The distribution of hypocenter relocations show that aftershock ruptured distribute between two block of high gravity anomaly, its indicate that it was not the new fault. The inversion of the source model shows several time periods of energy release with three main peaks. These temporal rupture suggest repetition of a large scale slip on the large asperity. The models of coulomb stress indicate that static stress transfer due to the Mw 7.4 earthquake is suitable with aftershock spatial distribution. We compute the probabilistic seismic hazard assessment in the Flores region for Earthquake mitigation