资源环境科技发展态势分析平台

We constrained the rupture process of the 25 October 2018 M(w)6.8 Zakynthos earthquake by jointly inverting near-fault strong motion records, static, and high-rate GPS displacements along with teleseismic waveforms. The inverted slip distribution is characterized by two asperities with peak slip amplitude of 1.4 m, which is located at 17 km depth. The rupture essentially propagated unilaterally in the downdip direction after the initiation and to the north-northeast toward Zakynthos island. The earthquake produced a deep rupture whose downdip extent approached 38 km, indicating that this event broke the entire underthrust Ionian oceanic crust beneath the megathrust and penetrated into the top few kilometers of the solid uppermost mantle. The extent of the rupture implied the presence of a low coefficient of dynamic friction. The mainshock triggered a counterclockwise rotation of the stress field with respect to the long-term regional stress. Aftershocks occurred at shallower depths than the coseismic slip zone.