Seismo-geodetic characterization of the Tuzla Fault (İzmir/Turkey) : |its kinematics and earthquake potential

Abstract

Izmir, the third largest city of Turkey, located in western coast of the country is seismically super active due to Hellenic subduction zone and extensional back-arc basin under the Aegean Sea. This tectonic environment has attened the cities in the region again and again as reported in the historical records. Hence, investigating the seismically active faults in the region is crucial to elaborate on earthquake hazard for the cities along the Western Turkey. In this context, we jointly analyzed geodetic, geological and seismological data to investigate latest failure, present day deformation, slip accumulation and fault kinematics along the Tuzla Fault. Historical and recent earthquakes were investigated to determine the latest failure of the Fault and result reveals that there is no evidence of a large earthquake failing the Fault entirely since 1688. Six epochs GPS measurements of fteen stations were analyzed for the time period of 2009-2017 to obtain horizontal tectonic slip rates along the Tuzla Fault. As a result, overall southwest movements change between 26.67 1.03 mm/yr and 28.96 1.00 mm/yr with respect to Eurasia. Di erential slip rates range between 1.00 to 2.00 mm/yr. Magnitude calculations were done for Tuzla Fault and its segments seperately. Tuzla Fault has currently a potential to generate a strong earthquake up to M6.2-M6.8. Strain analysis results show that the Çatalca Segment and northern Orhanlı Segment, accumulates high shear strain and therefore accommodate higher potential for co-seismic slip. According to fault plane solutions and maximum shear strain values and planes, Cumalı Segment has dextral characteristic, however, maximum shear strain planes indicates sinistral structure in Çatalca Segment.