Rupture behavior of the 2017 MW6.6 Poso earthquake in Sulawesi, Indonesia

On May 29, 2017, the M(W)6.6 Poso earthquake occurred in Central Sulawesi, Indonesia, causing moderate damages. The mainshock rupture and primary aftershock cluster occurred in the active Palolo-Sausu tectonic zone, and some aftershocks also took place around the Tokararu fault. However, the rupture mechanism of this earthquake and its relation to regional tectonics are not clear. In this study, the rupture process of the Poso mainshock is estimated by finite-fault waveform inversion, which is constrained by teleseismic bodies and surface waves. The rupture propagates upward unilaterally in a southwest-dipping moderate-angle (similar to 34 degrees) normal fault beneath Tokorondo Mountains, with a notable similar to 15% initial moment release at the first 4s of the similar to 12s rupture duration. The average and peak slip are 0.5 m and 1.5 m, respectively. The rupture velocity is relatively slow (less than 2.5 km/s), and the Coulomb stress changes due to the mainshock are obtained using the inverted coseismic slip. (C) 2021 Editorial office of Geodesy and Geodynamics. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.