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Abstract :
[en] The East Anatolian Fault (EAF) is a major left-lateral strike-slip fault accommodating with the conjugate North Anatolian Fault the westward extrusion of the Anatolian Plate away from the Arabia-Eurasia collision zone. During the 20th century, the EAF activity was mostly quiestcent with only two events of magnitude greater than 6 recorded (1905 Malatya and the 1971 Bingol earthquakes). Historical seismicity suggests that the EAF is capable of generating earthquakes of magnitude greater than 7. In order to retrace the seismic history of the EAF in its central part, we study Hazar Lake. Hazar Lake is a 20 km long pull-apart basin with a maximum depth of 216 m. Short cores and long sediment cores were collected at four different sites to retrieve a paleoseismological record. Detailed analysis of the sediment cores (e.g. magnetic susceptibility, XRF, XRD, thin sections) were performed to identify sedimentary events. The ages of the sedimentary events were inferred based on a detailed age-depth model combining radiocarbon dating and 137Cs/210Pb. In total, 65 radiocarbon dating were done on bulk sediment and on terrestrial organic matter. The results show that Hazar Lake region was impacted by two fault zones: The East Anatolian Fault (EAF) and the North Anatolian Fault. Based on historical documents, the seismic intensity of each seismic event recorded in Hazar Lake was calculated. Here, we discuss the seismic threshold for earthquake records as well as the seismic recurrence pattern for the EAF over the last 3000 years.
