Rupture Process of the 2020 Mw7.0 Samos Earthquake and its Effect on Surrounding Active Faults

On October 30, 2020, a M(w)7.0 normal faulting earthquake struck the eastern Aegean Sea, causing casualties, and substantial damage at Samos island and Izmir province. We constrained the rupture history of the main shock by jointly inverting GPS static offsets, high-rate GPS recordings, strong motion waveforms, and teleseismic broadband data. The results revealed that the slip distribution was dominated by a slip patch which spans a depth range of 3-13 km and occupies similar to 30 km along strike. The rupture propagated toward SW and updip and the maximum slip amplitude reached 4.6 m at 7 km depth. The remarkably low aftershock productivity within the main asperity suggests a near complete stress release. Coseismic Coulomb stress changes effectively explain the entire aftershock sequence implying absence of short-term postseismic stress transfer mechanisms. The static stress change calculations also suggest that active faults around Sigacik and Kusadasi Bays have been brought closer to rupture.

Automated summary

On October 30, 2020, a M(w)7.0 normal faulting earthquake struck the eastern Aegean Sea, causing casualties, and substantial damage at Samos island and Izmir province. By analyzing the rupture history of the main shock, it was found that the slip distribution was dominated by a slip patch spanning a depth range of 3-13 km. The low aftershock productivity within the main asperity implies a near complete stress release.