tailieunhanh - Simulation of seismic triggering and failure time perturbations associated with the 30 October 2020 Samos earthquake (Mw 7.0)

In this study, numerical simulations are conducted to mimic the instant and delayed seismic triggering observed after this event and evaluate resultant seismic cycle perturbations at adjacent faults and near İzmir, where amplified ground motions caused heavy damage. For this purpose, Coulomb static stress changes and seismic waveforms recorded by strong-motion stations are combined as static and dynamic triggers on a rate-and-state friction dependent quasi-dynamic spring slider model with shear-normal stress coupling. | Turkish Journal of Earth Sciences Turkish J Earth Sci http earth 2021 30 653-664 TÜBİTAK Research Article doi yer-2104-6 Simulation of seismic triggering and failure time perturbations associated with the 30 October 2020 Samos earthquake Mw Eyüp SOPACI1 Atilla Arda ÖZACAR1 2 1 Geodesy and Geographic Information Technology Middle East Technical University Ankara Turkey 2 Department of Geological Engineering Faculty of Engineering Middle East Technical University Ankara Turkey Received Accepted Published Online Final Version Abstract The 30 October 2020 Samos earthquake Mw ruptured a north-dipping offshore normal fault north of the Samos Island with an extensional mechanism. Aftershocks mainly occurred at the western and eastern ends of the rupture plane in agreement with the Coulomb static stress changes. Mechanism of aftershocks located west of the rupture supported activation of the neighboring strike-slip fault almost instantly. In addition a seismic cluster including events with Mw 4 has emerged two days later at the SE side of Samos Island. This off-plane cluster displays a clear example of delayed seismic triggering at nearby active faults. In this study numerical simulations are conducted to mimic the instant and delayed seismic triggering observed after this event and evaluate resultant seismic cycle perturbations at adjacent faults and near İzmir where amplified ground motions caused heavy damage. For this purpose Coulomb static stress changes and seismic waveforms recorded by strong-motion stations are combined as static and dynamic triggers on a rate-and-state friction dependent quasi-dynamic spring slider model with shear-normal stress coupling. According to our results earthquakes with Mw can be triggered instantly and Mw 4 events noticeably advance in failure time. However instant triggering occurs only when static stress loading is very high and the fault is close to fail .