2:45 PM - 3:00 PM
[SSS13-10] Paleoseismic investigations at Kartal site on an un-ruptured section along the East Anatolian fault system, Turkey
★Invited Papers
Keywords:active fault, paleoseismology, East Anatolian fault system, historical earthquake
The East Anatolian fault system (EAFS) forms extends with the strike of north-east to south-west, and it forms plate boundary transform faults between Anatolia micro-plate and Arabia plate. The northeastern termination of NAFS is located near the Karliova triple junction between Anatolia, Arabia and Eurasia plates. The location of the southwestern termination is still under discussion, but the most recently published active fault map (Emre et al., 2013) reveals that the southwestern section of the EAFS extends and connects to the Dead Sea fault system, that bounds the Arabian and African plates with the north-south strike. The length of the EAFS is longer than about 600 km on land. The left-lateral strike slip rate on the EAFS is estimated to be about 10 mm/yr by GPS (McClusky et al., 2000; Reilinger et al., 2006), InSAR (Walters et al., 2014), and geomorphic and geologic (e.g., Herece, 2008)
Geological Survey of Japan, AIST and MTA have worked together since 2014 under the international cooperative study on the paleoseismological studies on the EAFS. We here present the preliminary results of the Kartal trench studies in 2014. The Kartal site is located about 20 km east of Karhramanmaras, and it is on the Pazarcik segment which extends for ca. 90 km long. The segment is estimated to be one of seismic gaps along the NAFS, based on the latest two events of AD 1513 and AD 1114 (Duman and Emre, 2013; Hubert-Ferrari et al., 2020). The next segment to the south is the Amanos segment, and it extends for about 110 km connecting to the DSFS. The most recent event might be correlated with the AD 521, suggesting longer recurrence interval than the Pazaricik segment. During the 2023 event, the Mw 7.8 ruptured at least the Pazarcik and Amanos segments, and most probably with the Erkenek segment. We discuss the relation with the results of the 2014 Kartal trench, long-term evaluation at that time, and the actual multi-segment rupture during the 2023 Mw 7.8 event.
After the 2014 research, we re-visited the Kartal site and surrounding region in 2022. Our plan was to re-excavate 3-D trench at the Kartal site in the field season of 2023. Unfortunately, the destructive earthquake, Mw 7.8, has already occurred on the EAFS. The first reconnaissance survey immediately after the earthquake reveals that remarkable surface rupture appeared, and the amount of left-lateral offset was 3.8-4.1 meter at the site (Hasan Elmaci personal communication). We will continuously collect more reliable and accurate data in order to verify and improve the evaluation methods of long-term activity of the EAFS.
This work is a part of GSJ-MTA Joint research project ‘Paleoseismological Study on the East Anatolian Fault System, Turkey’
Geological Survey of Japan, AIST and MTA have worked together since 2014 under the international cooperative study on the paleoseismological studies on the EAFS. We here present the preliminary results of the Kartal trench studies in 2014. The Kartal site is located about 20 km east of Karhramanmaras, and it is on the Pazarcik segment which extends for ca. 90 km long. The segment is estimated to be one of seismic gaps along the NAFS, based on the latest two events of AD 1513 and AD 1114 (Duman and Emre, 2013; Hubert-Ferrari et al., 2020). The next segment to the south is the Amanos segment, and it extends for about 110 km connecting to the DSFS. The most recent event might be correlated with the AD 521, suggesting longer recurrence interval than the Pazaricik segment. During the 2023 event, the Mw 7.8 ruptured at least the Pazarcik and Amanos segments, and most probably with the Erkenek segment. We discuss the relation with the results of the 2014 Kartal trench, long-term evaluation at that time, and the actual multi-segment rupture during the 2023 Mw 7.8 event.
After the 2014 research, we re-visited the Kartal site and surrounding region in 2022. Our plan was to re-excavate 3-D trench at the Kartal site in the field season of 2023. Unfortunately, the destructive earthquake, Mw 7.8, has already occurred on the EAFS. The first reconnaissance survey immediately after the earthquake reveals that remarkable surface rupture appeared, and the amount of left-lateral offset was 3.8-4.1 meter at the site (Hasan Elmaci personal communication). We will continuously collect more reliable and accurate data in order to verify and improve the evaluation methods of long-term activity of the EAFS.
This work is a part of GSJ-MTA Joint research project ‘Paleoseismological Study on the East Anatolian Fault System, Turkey’