The 2017 Ayvacık Earthquake Sequence: A Listric Fault Activated Beneath Tuzla/Çanakkale Geothermal Reservoir (Western Turkey)

Abstract

We investigate seismo-geodetic behavior of the Earth’s crust during the 2017 Ayvacık earthquake sequence in Western Turkey. The activated fault did not accommodate any M≥5.0 earthquake during instrumental period except the recent sequence of M≥5.0 earthquakes in 2017. High-resolution earthquake locations identified that these earthquakes and associated pre- and aftershocks have activated a listric fault below Tuzla/Çanakkale geothermal reservoir. InSAR images show that the whole process led to a subsidence of ~8 cm in line-of-sight (LOS). The results show that the seismic activity started almost at the surface and systematically propagated downward as well as sideward through the entire listric fault reaching down to the seismogenic basement. Results verify that seismographs are indispensible instruments to identify structural variation as well as to implement hazard mitigation measures in geothermal fields.