22.01.2020 Akhisar-Manisa Depremi (Mw 5.5) ve Artçılarının Sismotektonik Analizi

Yıl 2020, Cilt: 2 Sayı: 1, 27 - 46, 29.06.2020

Tahir Serkan Irmak , Bülent Doğan , Evrim Yavuz , Hamdullah Livaoğlu , Fadime Sertçelik

https://doi.org/10.46464/tdad.730335

Cited By: 2

Öz

Bu çalışmada, 22 Ocak 2020 Akhisar-Manisa (M_w 5.5) depremi ve artçılarının odak mekanizması çözümleri dalga şekli ters çözümü ile elde edilmiş ve buna göre sismotektonik yorum yapılmıştır. Bu amaçla, ana şok ve 35 artçı depremin odak mekanizması çözümleri ISOLA algoritması ile elde edilmiştir. Depremlerin odak mekanizması çözümlerinin çoğunluğu, bölgenin genişleme tektoniği ile uyumlu olup, normal faylanma ve az miktarda doğrultu atım bileşeni olan normal faylanma veya normal faylanma bileşeni olan doğrultu atımlı faylanma özelliğine sahiptir. Analizi yapılan depremlerin odak derinlikleri 4-15 km arasında değişmektedir. Gerilme tensörü ters çözümüne göre; bölge açılma rejiminin (R’=0.75) etkisi altındadır ve KD-BG yönünde açılmaktadır. Açılma hızı 1.3 mm/yıl olarak hesaplanmıştır. Bölgede minimum basınç ekseni (σ3), K21^oD olarak yönlenmiştir. Asal gerilme eksenlerinin bölgedeki konumları sırasıyla σ_1, σ_2, ve σ_3 olmak üzere 74^o /111^o, 16^o/291^o ve 0^o/201^o (eğim/azimut) olarak hesaplanmıştır. Bu stres dağılımlarına göre depremlerin üzerlerinde meydana geldiği fay düzlemleri, gerilmeli tektonik kabuk deformasyonunu işaret etmektedir.

Anahtar Kelimeler

Deprem kaynak mekanizması, moment tensör analizi, KB doğrultulu normal fay, gerilme tektoniği

Destekleyen Kurum

Kocaeli Üniversitesi

Teşekkür

Yazarlar KRDAE ve AFAD personeline deprem verilerini son kullanıcıya açtıkları için teşekkür ederler. Yazarlar, makalenin düzeltme aşamasındaki katkılarından dolayı hakemlere ve Editör’e teşekkür ederler.

Focal Mechanisms of the January 22, 2020 Akhisar-Manisa Earthquake (Mw 5.5) and Its Aftershocks: Seismotectonic Implications

Öz

Focal mechanism solutions of the January 22, 2020 Akhisar-Manisa (M_w 5.5) earthquake and its aftershocks were obtained by using moment tensor inversion in order to make a seismotectonic interpretation for the study area. Total of 35 focal mechanism including the main shock have been obtained by using ISOLA algorithm. The results indicated that the majority of the focal mechanism solutions are normal faulting and normal faulting with strike slip component and some are strike slip faulting with normal faulting component. The results are compatible with the tectonics of the region. Focal depths of the analysed earthquakes are ranging between 4 and 15 km. The stress inversion of the studied earthquakes show that the present-day stress field is characterized by pure extensional regime (R’=0.75) and the study area is opening NE-SW. The horizontal direction of extension at N21^o E. Axis orientations are found as 74^o /111^o, 16^o/291^o and 0^o/201^o (dip/azimuth direction) for σ_1, σ_2, and σ_3, respectively. According to these stress distributions, the fault planes on which earthquakes occur indicate extensional tectonic crustal deformation.

Anahtar Kelimeler

Earthquake Source Mechanism, moment tensor analysis, NW trending normal fault, extensional tectonics

Kaynakça

• Akyol N., Zhu L., Mitchell B.J., Sozbilir H., Kekovali K., 2006. Crustal structure and local seismicity in western Anatolia. Geophys. J. Int., 166(3), 1259-1269.
• Alsan E., Tezucan L., Bath M., 1976. An earthquake catalogue for Turkey for the interval 1913–1970. Tectonophysics, 31(1-2), T13-T19.
• Ambraseys N.N., 1988. Engineering seismology: part I. Earthquake Engineering & Structural Dynamics, 17(1), 1-50.
• Angelier J., Mechler P., 1977. Sur une méthode graphique de recherche des contraintes principales également utilisable en tectonique et en séismologie: la méthode des dièdres droits. Bulletin de la Société géologique de France, 7(19), 1309-1318.
• Bouchon M., 1981. A simple method to calculate Green's functions for elastic layered media. Bulletin of the Seismological Society of America, 71(4), 959-971.
• Bozkurt E., 2000. Timing of extension on the Büyük Menderes Graben, western Turkey, and its tectonic implications. Geological Society, London, Special Publications, 173(1), 385-403.
• Bozkurt E., Mittwede S.K., 2005. Introduction: Evolution of continental extensional tectonics of western Turkey. Geodinamica Acta, 18(3-4), 153-165.
• Brune J.N., 1968. Seismic moment, seismicity, and rate of slip along major fault zones. Journal of Geophysical Research, 73(2), 777-784.
• Delvaux D., 1993. The TENSOR program for paleostress reconstruction: examples from the east African and the Baikal rift zones. TERRA nova, 5(1), 216.
• Delvaux D., Moeys R., Stapel G., Petit C., Levi K., Miroshnichenko A., Ruzhich V., San'kov V., 1997. Paleostress reconstructions and geodynamics of the Baikal region, central Asia, Part 2. Cenozoic rifting. Tectonophysics, 282(1-4), 1-38.
• Delvaux D., Sperner B., 2003. Stress tensor inversion from fault kinematic indicators and focal mechanism data: the TENSOR program. New insights into structural interpretation and modelling, 212, 75-100.
• Dewey J.F., Sengor A.C., 1979. Aegean and surrounding regions: complex multiplate and continuum tectonics in a convergent zone. Geological Society of America Bulletin, 90(1), 84-92.
• Dogan B., Irmak T.S., Karakas A., Kalafat D., 2016. Seismotectonic content by the source parameters of the 10 June 2012 Ölüdeniz-Fethiye (Dodecanese Islands) Mw 6.1 earthquake and aftershocks (southwestern Turkey). Acta Geodaetica et Geophysica, 51(1), 15-41.
• Ergin K., Güçlü U., Uz Z., 1967. A catalog of Earthquake for Turkey and Surrounding Area (11 A.D. to 1964 A.D.). ITU Faculty of Mining Engineering, Istanbul, Turkey.
• Eyidoğan H., Güçlü U., Utku Z., Değirmenci E., 1991. Türkiye büyük depremleri makrosismik rehberi (1900-1988). Kurtiş Matbaası, İstanbul.
• Eyidogan H., Jackson J., 1985. A seismological study of normal faulting in the Demirci, Alaşehir and Gediz earthquakes of 1969–70 in western Turkey: Implications for the nature and geometry of deformation in the continental crust. Geophys. J. Int., 81(3), 569-607.
• Fojtíková L., Vavryčuk V., Cipciar A., Madarás J., 2010. Focal mechanisms of micro-earthquakes in the Dobrá Voda seismoactive area in the Malé Karpaty Mts.(Little Carpathians), Slovakia. Tectonophysics, 492(1-4), 213-229.
• Gurer O.F., Kaymakci N., Cakir S., Ozburan M., 2003. Neotectonics of the southeast Marmara region, NW Anatolia, Turkey. Journal of Asian Earth Sciences, 21(9), 1041-1051.
• Holt W.E., Ni J.F., Wallace T.C., Haines A.J., 1991. The active tectonics of the eastern Himalayan syntaxis and surrounding regions. Journal of Geophysical Research: Solid Earth, 96(B9), 14595-14632.
• Irmak T.S., 2013. Focal mechanisms of small-moderate earthquakes in Denizli Graben (SW Turkey). Earth, Planets and Space, 65(9), 943-955.
• Irmak S., Taymaz T., 2009. Source mechanics of recent moderate earthquakes occurred in Honaz-Denizli (W Turkey) graben obtained by regional broadband waveform inversion. In International Symposium on Historical Earthquakes and Conservation of Monuments in the Eastern Mediterranean Region, Istanbul, Turkey (pp. 350-356).
• Jackson J., McKenzie D., 1984. Active tectonics of the Alpine—Himalayan Belt between western Turkey and Pakistan. Geophys. J. Int., 77(1), 185-264.
• Kartal R.F., Demirtaş R., Kadirioğlu F.T., 2016. Seismotectonic Evaluation of August 08, 2019 Bozkurt (Denizli) Earthquake (Mw 6.0): Western Turkey. Erişim Adresi: https://www.researchgate.net/publication/336719706_Seismotectonic_Evaluation_of_August_08_2019_Bozkurt_Denizli_Earthquake_Mw_60_Western_Anatolia
• Kaypak B., Gokkaya G. 2012. 3-D imaging of the upper crust beneath the Denizli geothermal region by local earthquake tomography, western Turkey. Journal of Volcanology and Geothermal Research, 211, 47-60.
• Kikuchi M., Kanamori H., 1991. Inversion of complex body waves—III. Bulletin of the Seismological Society of America, 81(6), 2335-2350.
• Kocyigit A., Yusufoglu H., Bozkurt E., 1999. Evidence from the Gediz graben for episodic two-stage extension in western Turkey. Journal of the Geological Society, 156(3), 605-616.
• McClusky S., Balassanian S., Barka A., Demir C., Ergintav S., Georgiev I., Gurkan O., Hamburger M., Hurst K., Kahle H., Kastens K., Kekelidze G., King R., Kotzev V., Lenk O., Mahmoud S., Mishin A., Nadariya M., Ouzounis A., Paradissis D., Peter Y., Prilepin M., Reilinger R., Sanli I., Seeger H., Tealeb A., Toksoz M.N., Veis G., 2000. Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. Journal of Geophysical Research: Solid Earth, 105(B3), 5695-5719. https://doi.org/10.1029/1999JB900351
• Ozer C., Gok E., Polat O., 2018. Three-dimensional seismic velocity structure of the Aegean Region of Turkey from local earthquake tomography. Annals of Geophysics, 61(1), 111.
• Ozer C., Polat O., 2017. 3-D crustal velocity structure of İzmir and surroundings. Journal of the Faculty of Engineering and Architecture of Gazi University, 32, 733-747.
• Sengor A.M.C., 1987. Cross-faults and differential stretching of hanging walls in regions of low-angle normal faulting: examples from western Turkey. Geological Society, London, Special Publications, 28(1), 575-589.
• Seyitoglu G., Scott B.C., 1996. The cause of N–S extension altectonics in western Turkey: Tectonic escape vs back-arc spreading vs. orogenic collapse J. Geodyn., 22 (1996), pp. 145-153.
• Sokos E.N., Zahradnik J., 2008. ISOLA a Fortran code and a Matlab GUI to perform multiple-point source inversion of seismic data. Computers & Geosciences, 34(8), 967-977.
• Sokos E.N., Zahradnik J., 2013. Evaluating centroid‐moment‐tensor uncertainty in the new version of ISOLA software. Seismological Research Letters, 84(4), 656-665.
• Soysal H., Sipahioğlu S., Kolcak D., Altinok Y., 1981. Turkiye ve Cevresinin Tarihsel deprem Katalogu. TUBITAK, Proje no. TBAG 341, Istanbul, 86 pp.
• Taymaz T., Jackson J., McKenzie D., 1991. Active tectonics of the north and central Aegean Sea. Geophys. J. Int., 106(2), 433-490.
• Taymaz T., Price S., 1992. The 1971 May 12 Burdur earthquake sequence, SW Turkey: a synthesis of seismological and geological observations. Geophys. J. Int., 108(2), 589-603.
• Tepe C., Sozbilir H., 2017. Tectonic geomorphology of the Kemalpaşa Basin and surrounding horsts, southwestern part of the Gediz Graben, Western Anatolia. Geodinamica Acta, 29(1), 70-90.
• Zhu L., Mitchell B.J., Akyol N., Cemen I., Kekovali K., 2006. Crustal thickness variations in the Aegean region and implications for the extension of continental crust. Journal of Geophysical Research: Solid Earth, 111(B1).
• URL-1; KRDAE-BDTİM, Boğaziçi Üniversitesi Kandilli Rasathanesi ve Deprem Araştırma Enstitüsü Bölgesel Deprem ve Tsunami İnceleme Merkezi, Erişim adresi: http://www.koeri.boun.edu.tr/sismo/2/deprem-bilgileri/buyuk-depremler/
• URL-2; MTA, Maden Tetkik ve Arama Genel Müdürlüğü, Erişim adresi: https://www.mta.gov.tr/v3.0/hizmetler/yenilenmis-diri-fay-haritalari
• URL-3; KRDAE-BDTİM, Boğaziçi Üniversitesi Kandilli Rasathanesi ve Deprem Araştırma Enstitüsü Bölgesel Deprem ve Tsunami İnceleme Merkezi, Erişim adresi: http://www.koeri.boun.edu.tr/sismo/2/deprem-verileri/sayisal-veriler/
• URL-4; AFAD, T.C. İçişleri Bakanlığı Afet ve Acil Durum Yönetimi Başkanlığı Deprem Dairesi Başkanlığı, Erişim adresi: http://tdvm.afad.gov.tr/