Tetiklenmiş depremsellik ve jeotermal sistemler arasındaki ilişki: Gediz grabeni örneği, Batı Anadolu, Türkiye

It is well known that pore pressure and stress variation trigger earthquakes when a potentially active fault or crack is in critical equilibrium. This study examines the effects of geothermal energy activities on seismicity, which accelerated in the Gediz Graben in 2011-2012. Geothermal fluid in Gediz Graben comes into existence from tectonic zones of low angle Gediz Detachment Fault (GDF) of Quaternary age and high angle normal faults of Holocene age. For indirect and direct use of geothermal energy, many wells with production and reinjection functions have been drilled in the Gediz Graben (GG) at depths of 600-4300 m. Geothermal production, reinjection, and seismic data were assessed together with the structural geology of the study area by using the Geographic Information System-based programs. These results show that an increase in seismicity was observed simultaneously with the excavation and testing of geothermal wells. It was terminated that earthquakes of 0.9 - 3.4 magnitude in the study area may be related to geothermal activity. In addition to the geothermal production - reinjection process, micro-earthquakes were observed during the drilling operations and well tests, which may occur due to the reactivation of pre-existing faults. Regarding the geothermal power plants in Gediz Graben, the relationship between geothermal production, reinjection activities, and seismicity should be determined, predicted, and controlled by the "traffic light" system.