TURKISH JOURNAL OF EARTH SCIENCES, cilt.30, sa.4, ss.436-448, 2021 (SCI-Expanded)
A Mw 6.8 earthquake struck Western Turkey and Eastern Greece that occurred on October 30, 2020 in Kupdast Gulf. The earthquake epicentre is located north of Samos Island and the focal mechanism solution shows that a normal fault was reactivated. The main shock and aftershock analysis imply that the large earthquake occurred on a north dipping normal fault which might be the western continuation of the Efes Fault in Western Turkey. We propose that the western continuation of the Efes Fault steps over right somewhere in northeast of Samos Island and continues further west along the northwest margin of the island, in the form of a transfer fault between two segments. The aftershock distribution shows that both the western segment and the transfer fault were reactivated during the 30 October 2020 earthquake. This fault geometry can be compared with the E-W trending Gediz Graben where the southern boundary fault steps over right around Turgutlu and continues further west in Manisa.