Abstract
An earthquake of Mw 7.8 occurred on 6 February 2023 at a depth of 18 km on the NE-SW trending East Anatolian Fault (EAF) in southern Turkey bordering Syria. This is the first time that an earthquake of Mw≥7.0 has occurred on EAF since 1900. The region lies on the triple-junction between the Arabian, African and Anatolian plates. The epicenter was located 32 km WNW of the Gaziantep city close to the Kahramanmaras Triple Junction (KMTJ) where the NNE-SSW Dead Sea transform fault (DSF) intersects the EAF. Based on the distribution of immediate aftershocks of 4.0≤Mw≤6.7 it is inferred that the fault rupture was bidirectional and broke a ∼300 km fault length of EAF in three segments of Amanos, Pazarcik and Erkenek. This earthquake triggered an event of Mw7.5 on the E-W Surgu Fault, ∼100 km north of the mainshock. Eleven cities suffered the worst damage where several multistoried structures collapsed killing more than 43,000 people. While the structures in the epicentral region collapsed due to very strong shaking induced by these two shallow and large earthquakes the collapse of structures in cities as far as 300 km suggests strong role of seismic wave amplification due to local site effects in addition to poor construction practices and non-compliance of seismic codes. The rupture of a ∼300 km fault length in three segments of EAF and its influence to trigger future large earthquakes in the adjacent four segments of Puturge, Palu, Ilica and Karliova in eastern Turkey by stress transfer in a cascading manner is discussed.
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References
Ambraseys, N.N. and Jackson, J.A. (1998) Faulting associated with historical and recent earthquakes in the Eastern Mediterranean region. Geophys. Jour. Int, v.133, pp.390–406.
Arpat, E. and Saroglu, F., (1972) The East Anatolian Fault system: thoughts on its development. Bull. Miner. Res. Explor. Inst. Turkey. v.78, pp.33–39.
Barka, A.A. (1992) The North Anatolian fault zone, Ann. Tectonicae, v.6, pp.164–195.
Bletery, Q., Cavalie ì, O., Nocquet, J.M. and Ragon, T., (2020) Distribution of interseismic coupling along the north and east Anatolian faults inferred from InSAR and GPS data. Geophys. Res. Lett., v.47, pp.1–11.
Duman, T.Y. and Emre, O. (2013) The East Anatolian Fault: geometry, segmentation and jog characteristics. Geol. Soc. Spec. Publ, v.372, pp.495–529.
Durand, V. et al., (2010). Seismic interaction and delayed triggering along the North Anatolian Fault. Geophys. Res. Lett, v.37(18), doi:https://doi.org/10.1029/2010GL044688.
Flerit, F., Armijo, R., King, G and Meyer, B., (2004) The mechanical interaction between the propagating North Anatolian Fault and the back arc extension in the Aegean. Earth Planet. Sci. Lett, v.224(3–4), pp.347–362, doi:https://doi.org/10.1016/j.epsl.2004.05.028.
Fraser, J., Vanneste, K and Hubert Ferrari. (2010) Recent behavior of the North Anatolian Fault: Insights from an integrated paleoseismological data set. Jour. Geophys. Res., v.115, B09316, doi:https://doi.org/10.1029/2009JB006982.
Gallovic, F., Zahradnik, J., Plicka, V., Sokos, E., Evangelidis, C., Fountoulakis, I. and Turhan, F. (2020) Complex rupture dynamics on an imma- ture fault during the 2020 Mw 6.8 Elazig earthquake, Turkey. Commun. Earth Environ, v.1, pp.1–8.
Hartleb, R. D., Dolan, J.F., Kozaci, O, Akyüz, H.S and Seitz, GG., (2006) A 2500 yr long paleoseismologic record of large, infrequent earthquakes on the North Anatolian Fault at Çukurçimen, Turkey. Bull. Geol. Soc. Amer., v.118(7), pp.823–840, doi:https://doi.org/10.1130/B25838.1.
Hempton, M.R., Dewey, J.F. and Saroglu, F., (1981). The East Anatolian transform fault: along strike variations in geometry and behavior. EOS, Trans. Amer. Geophys. Union, v.62, pp.393.
Isk, S.E., Konca, A.O and Karabulut, H. (2017) The seismic interactions and spatiotemporal evolution of seismicity following the October 23, 2011 Mw 7.1 Van, Eastern Anatolia, earthquake. Tectonophysics, v.702, pp.8–18.
King, G.C.P., Stein, R.S. and Lin, J., (1994). Static stress changes and the triggering of earthquakes. Bull. Seism. Soc. Amer, v.84, doi:https://doi.org/10.1016/0148-9062(95)94484-2.
Konca, A.O. et al., (2021). From interseismic deformation with near-repeating earthquakes to co-seismic rupture: a unified view of the 2020 Mw6.8 Sivrice (Elazýg) Eastern Turkey Earthquake. Jour. Geophys. Res., v.126–10, e2021JB021830
Le Pichon, X. and Kreemer, C., (2010) The miocene-to-present kinematic evo- lution of the eastern mediterranean and middle east and its implications for dynamics. Annu. Rev. Earth Planet. Sci., v.38, pp.323–351.
Mahmoud, Y. et al., (2013) Kinematic study at the junction of the East Anatolian Fault and the dead sea fault from GPS measurements. Jour. Geodyn., v.67, pp.30–39
McKenzie, D. (1972) Active tectonics of the Mediterranean region. Geophys. Jour. Int., v.30, pp.109–185.
Pantosti, D., Pucci, S, Palyvos, N, De Martini, P.M., D’Addezio, G Collins, P.E.P. and Zabci, C., (2008) aleoearthquakes of the Duzce fault (North Anatolian fault zone): Insights for large surface faulting earthquake recurrence. Jour. Geophys. Res., v.113, B01309, doi:https://doi.org/10.1029/2006JB004679.
Pousse-Beltran, L., Nissen, E., Bergman, E.A., Cambaz, M.D., Gaudreau, E. ì., Karaso zen, E. and Tan, F., (2020). The 2020 Mw 6.8 Elazig (Turkey) earthquake reveals rupture behavior of the East Anatolian Fault. Geophys. Res. Lett., v.47, e2020GL088136. doi:https://doi.org/10.1029/2020GL088136
Pondard, N., Armijo, R., King, G.C.P., Meyer, B and F. Flerit., (2007) Fault interactions in the Sea of Marmara pull apart (North Anatolian Fault): Earthquake clustering and propagating earthquake sequences. Geophys. Jour. Int., v.171, pp.1185–1197, doi:https://doi.org/10.1111/j.1365-246X.2007.03580.x.
Reilinger, R. and McClusky, S. (2011) Nubia-Arabia-Eurasia plate motions and the dynamics of Mediterranean and Middle East tectonics. Geophys. Jour. Int, v.186, pp.971–979.
Rockwell, T., et al. (2009), Palaeoseismology of the North Anatolian Fault near the Marmara Sea: Implications for fault segmentation and seismic hazard. In: K. Reicherter, A. M. Michetti, and P. G. Silva (Eds.), Palaeoseismology: Historical and Prehistorical Records of Earthquake Ground Effects for Seismic Hazard Assessment. Geol. Soc. Spec. Publ., v.316(1), pp.31–54, doi:https://doi.org/10.1144/SP316.3.
Sengor, A.M.C., Gorur, N and S’aroglu, F. (1985) Strike slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study. In: K. T. Biddle and N. Christie Blick (Eds.), Strike Slip Deformation, Basin Formation, and Sedimentation. Soc. Econ. Paleontol. Mineral. Spec. Publ., v.37, pp.227–264.
Sengor, A., Tuysuz, O, Imren, C, Sakinc, M, Eyidogan, H, Gorur, N, Le Pichon, X and Rangin, C. (2005) The North Anatolian Fault: A new look. Annu. Rev. Earth Planet. Sci, v.33(1), pp.37–112, doi:https://doi.org/10.1146/annurev.earth.32.101802.120415.
Sezim Ezgi, Guvercin., Hayrullah Karabulut, Ozgun Konca., A., Ugur Dogan and Semih Ergintav (2022) Active seismotectonics of the East Anatolian Fault. Geophys. Jour. Int., v.230, pp.50–69
Stein, R.S., Barka, A.A. and Dieterich, J.H. (1997) Progressive failure on the North Anatolian fault since 1939 by earthquake stress triggering. Geophys. Jour. Int., v.128, pp.594–604.
Stern, R.J. and Johnson, P. (2010) Continental lithosphere of the Arabian plate: A geologic, petrologic and geophysical synthesis. Earth. Sci. Rev., v.101, pp.29–67, doi:https://doi.org/10.1016/j.earscirev.2010.01.002
USGS (2023). https://www.usgs.gov
Westaway, R. (2003) Kinematics of the Middle East and eastern Mediterranean updated. Turk. Jour. Earth Sci., v.12, pp.5–46.
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The support of the Director, CSIR-National Geophysical Research Institute, Hyderabad and the Atomic Energy Department, Government of India is gratefully acknowledged.
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Chadha, R.K. An Mw 7.8 Earthquake on 6 February 2023 on the East Anatolian Fault, Turkey. J Geol Soc India 99, 449–453 (2023). https://doi.org/10.1007/s12594-023-2331-z
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DOI: https://doi.org/10.1007/s12594-023-2331-z