21 Temmuz 2017 Mw 6.6 Bodrum-Kos depremi öncesi b-değerlerinin analizi

Yıl 2021, Cilt: 14 Sayı: 2, 382 - 394, 31.08.2021

Fahriye Akar

https://doi.org/10.18185/erzifbed.871960

Öz

Anahtar Kelimeler

depremsellik, b değeri, Bodrum-Kos depremi

Analysis of the b-Values Before the July 21 th, 2017 Mw 6.6 Bodrum-Kos, Turkey Earthquake

Öz

In this study, a statistical analysis of regional and time-dependent changes of earthquake activity in Bodrum and its vicinity before the Bodrum-Kos earthquake (Mw 6.6) that occurred on 21 July 2017 was performed and the Gutenberg-Richter b-value change was investigated. The earthquake catalog used in the calculations was taken from Boğaziçi University, Kandilli Observatory and Earthquake Research Institute. This catalog contains 16947 earthquakes with M>2 between 2004 and the time until the Bodrum-Kos earthquake of 21.07.2017. The completeness magnitude for these earthquakes was calculated as 2.6. The b-value was calculated as 1.25 ±0.01 using the maximum probability method. Considering that tectonic earthquakes have b-values between 0.5-1.5, it is seen that the b-value obtained by Gutenberg-Richter law for the vicinity of Bodrum in this study is a good fit. In addition, it was observed that b-value took high values in the north of Bodrum before the Bodrum-Kos earthquake occurred. Low values are observed in the southeast of Bodrum. Stress accumulation was correlated with b-values for the region.

Anahtar Kelimeler

Seismicity,, b-value, Bodrum-Kos earthquake

Kaynakça

• AFAD, 2017. Preliminary Evaluation Report of July 21th, 2017 Muğla-Bodrum Offshore Earthquake (in Turkish). Disaster and Emergency Management Authority, Ankara.
• Aki, K. 1965. “Maximum likelihood estimate of b in the formula log N = a – bM and its confidence limits”, Bulletin Earthquake Research Institute Tokyo University, 43, 237-239.
• Aktar, M., Karabulut, H., Childs, D., Mutlu, A., Ergin, M., Yörük, A., Gecgel, V., Bulut, F. and Kaya, T. 2006. “Gökova Körfezi (Muğla) Aktif Faylarında Güncel Sismik Aktivitenin Belirlenmesi”. TÜBITAK Projesi, No:104Y336, 29s.
• Altinok, Y. and Ersoy, S. 2000. “Tsunamis observed on and near the Turkish coast ” Natural Hazards, 21, 185–205.
• Ambraseys, N.N. and Finkel, C. 1991. “Long-term seismicity of Istanbul and of the Marmara Sea region”, Terra Motae, 3, 527-539.
• KOERI, 2017. “21 July 2017 Gökova Gulf - Mediterranean Earthquake Press Release”, Kandilli Observatory And Earthquake Research Institute Regional Earthquake Tsunami Monitoring and Evaluation Center.
• Crampin, S. ve Üçer, S. B. 1975, “The seismicity of the Marmara Sea region of Turkey”, Geophys. J. R. Astr. Soc., 40, 269-288.
• Dewey, J. F. and Şengor, A. M. C. (1979). “Aegean and surrounding regions: Complex multiplate and continuum tectonics in a convergent zone”. Geological Society of America Bulletin, 90, 89–92.
• Duman, T.Y., Emre, Ö., Özalp, S. and Elmacı, H. 2011. “1:250000 Ölçekli Türkiye Diri Fay Haritası, Aydın (NJ35-11) Paftası”, Seri No:7, Maden Tetkik ve Arama Genel Müdürlüğü, Ankara,Türkiye.
• Emre, Ö., Duman, T.Y. and Özalp, S. 2011. “1:250000 Ölçekli Türkiye Diri Fay Haritası, Marmaris (NJ35-15) Paftası”, Seri No:8, Maden Tetkik ve Arama Genel Müdürlüğü, Ankara,Türkiye.
• Enescu, B. and Ito, K. 2002. “Spatial analysis of the frequency-magnitude distribution and decay rate of aftershock activity of the 2000 Western Tottori earthquake”, Earth Planets Space, 54, 847–859.
• Fronlich, C. And Davis, S.D. 1990. “Teleseismic b-values; Or, much ado about 1.0”, Journal of Geophysical Research, Vol. 98, Is B1, 631-644.
• Görgün, E. 2013, Analysis of the b-values before and after the 23 October 2011 MW 7.2 Van-Erciş, Turkey earthquake. Tectonophysics, 603, 213-221.
• Gutenberg, B. ve Richter, C. F. 1944. “Frequency of earthquakes in California”, Bulletin of the Seismological Society of America, 34, 185-188.
• Gürbüz, C., Aktar, M., Eyidoğan, H., Cisternas, A., Haessler, H., Barka, A., Ergin, M., Türkelli, N., Polat, O., Üçer, S.B., Kuleli, S., Barış, S., Kaypak, B., Bekler, T., Zor, E., Biçmen, F., ve Yörük, A. 2000. “The seismotectonics of the Marmara region (Turkey): results from a microseismic experiment”, Tectonophysics, 316, 1-17.
• Gurer, O. F., Sangu, E., Ozburan, M., Gurbuz, A., SaricaFiloreau, N. 2013. “Complex basin evolution in the Gökova Gulf region: implications on the Late Cenozoic tectonics of southwest Turkey”, International Journal of Earth Sciences, 102, 2199–2221.
• Kalafat, D and Horasan, G. 2012. “A seismological view to Gökova region at southwestern Turkey”, International Journal of the Physical Sciences, 7(30), 5143-5153. McClusky, S., Balassanian, S., Barka, A., Demir, C., Ergintav, S., Georgiev, I., Gurkan, O., 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, 5695–5719.
• Mogi, K. 1962. “Study of the elastic shocks caused by the fracture of heterogeneous materials and its relation to earthquake phenomena”, Bulletin of the Eearthquke Research Institute, 40,125-173.
• C. Montuori, G. Falcone, M. Murru, C. Thurber, M. Reyners, D. Eberhart-PhillipsCrustal heterogeneity highlighted by spatial b-value map in the Wellington region of New Zealand, Geophysical Journal International, 183, 451-460.
• Öncel, A.O., Wyss, M., 2000. “The major asperities of the 1999 Mw = 7.4 Izmit earthquake defined by the microseismicity of the two decades before it”. Geophysical Journal International 143, 501–506.
• Öncel, A. O. ve Wilson, T. H. 2007. “Anomalous seismicity preceding the 1999 Izmit event, NW Turkey”, Geophysical Journal International, 169 (1), 259-270.
• Öztürk, S. 2017. “Regional and Temporal Variations of Current Earthquake Activity in and around Gümüşhane: A Statistical Assessment”, Gümüşhane Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 7 (1), 25-40.
• Pınar, N., Lahn, E.,1952. “Türkiye Depremleri İzahlı Kataloğu”, Bayındırlık Bakanlığı, Yapı ve İmar işleri Müdürlüğü, Ankara, No:6, 153s.
• Reilinger, R., McClusky, S., Vernant, P., Lawrence, S., Ergintav, S., Cakmak, R., … Karam, G. 2006. “GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions”. Journal of Geophysical Research, 111, B05411.
• Scholz, C. H. 1968. “The frequency-magnitude relation of microfracturing in rock and its relation to earthquakes”, Bulletin of the Seismological Society of America, 58, 399-416.
• Scholz, C.,H. 1990. “The Mechanics of Earthquakes and Faulting”, Cambridge Univ. Press, 439.
• Schorlemmer, D., Wiemer, S., Wyss, M., 2005. “Variations in earthquake-size distribution across different stress regimes”. Nature 437(04), 094.
• Schorlemmer, D., Wiemer, S., 2005. “Microseismicity data forecast rupture area”. Nature 434, 1086.
• Soysal, H., Sipahioğlu, S., Kolçak, D. and Altınok, Y. 1981. “Türkiye ve Çevresinin Tarihsel Deprem Kataloğu, (M.O. 2100 - M.S. 1900) ”, TÜBİTAK Proje No:TBAK-341.
• Sözbilir, H., Uzel., B., Sümer, Ö., Eski, S., Softa, M., Tepe, Ç. 2017. “21 Temmuz 2017 Gökova Körfezi Depremleri Ve Bölgenin Depremselliği Raporu”, Dokuz Eylül Üniversitesi Deprem Araştırma ve Uygulama Merkezi Diri Fay Araştırma Grubu Raporları Serisi, 14.
• Tiryakioglu, I., Aktuğ, B., Yiğit, C. Ö., Yavaşoğlu, H. H., Sözbilir, H., Özkaymak, Ç., Poyraz, F., Taneli, E., Bulut, F., Doğru, A. And Özener H. 2018. Slip distribution and source parameters of the 20 July 2017 Bodrum-Kos earthquake (Mw 6. 6) from GPS observations, Geodinamica Acta, 30(1), 1–14.
• Urbancic, T.I., Trifu, C.I., Long, J.M. and Young, R. P. 1992. “Space-time correlations of b values with stress release”, J. Geophys. Res., 139, 449-462.
• Utsu, T. 1966. “A statistical significance test of the difference in b value between two earthquake groups”, Journal of Physics Earth 14, 37–40.
• Utsu, T. 1999. “Representation and analysis of the earthquake size distribution: a historical review and some new approaches”, Pure and Applied Geophysics, 155, 509–535.
• Van Stiphout, T., Wiemer, S. and Marzocchi W. 2010. Are short‐term evacuations warranted? Case of the 2009 L'Aquila earthquake, Geophys. Res. Lett., 37, L06306.
• Voidomatis, PH. S., Pavlid, S. B. ve Papadopoulos, G. A. 1990. “Active Deformation and Seismic Potential in the Serbomacedonian Zone, Northern Greece”, Tectonophysics, 179, 1-9.
• Westerhaus, M., Wyss, M., Yilmaz, R., Zschau, J. 2002. Correlating variations of b values and crustal deformations during the 1990s may have pinpointed the rupture initiation of the Mw = 7.4 Izmit earthquake of 1999 August 17, Geophysical Journal International 148, 139–152.
• Wiemer, S. 2001. “A software package to analyze seismicity: ZMAP”. Seismological Research Letters, 72 (2), 374–383.
• Wiemer, S., Katsumata, K. 1999. “Spatial variability of seismicity parameters in aftershock zones”. Journal of Geophysical Research, 104, 13135–13151.
• Wiemer, S. ve Mcnutt, S., 1997. “Variations in frequency-magnitude distribution with depth in two volcanic areas: Mount St. Helens, Washington, and Mt. Spurr, Alaska”, Geophys. Res. Lett., 24, 189-192.
• Wiemer, S., Mcnutt, S. R. ve Wyss, M. 1998. “Temporal and three-dimensional spatial analysis of the frequency-magnitude distribution near Long Valley Caldera, California”, Geophys. J. Int, 134, 409-421.
• Wiemer, S., ve Wyss, M. 1994. “Seismic quiescence before the Landers (M=7.5) and Big Bear (6.5) 1992 earthquakes”, Bulletin of the Seismological Society of America, 84 (3), 900- 916.
• Wiemer, S. ve Wyss, M. 1997. “Mapping the frequency-magnitude distribution in asperities: An improved technique to calculate recurrence times? ”, J. Geophys. Res., 102, 15115-15128.
• Wiemer, S., ve Wyss, M. 2000. “Minimum magnitude of completeness in earthquake catalogs: Examples from Alaska, the Western United States, and Japan”, Bulletin Seismological Society of America, 90(4), 859-869.
• Wyss, M., Shimazaki, K. ve Wiemer, S. 1997. “Mapping active magma chambers by b value beneath Off-Izu volcano, Japan”, J. Geophys. Res., 102, 20,413- 20,433.
• Wyss, M., Sammis, C.G., Nadeau, R.M., Wiemer, S., 2004. Fractal dimension and b-value on creeping and locked patches of the San Andreas Fault near Parkfield, California, Bulletin of the Seismological Society of America, 94, 410.
• Yolsal, S., Taymaz, T. and Yalçiner, A.C. 2007. “Understanding tsunamis, potential source regions and tsunami-prone mechanisms in the Eastern Mediterranean”, Geological Society, London, Special Publications, 291, 201-230.
• Yolsal-Çevikbilen, S. and Taymaz, T. 2012. “Earthquake source parameters along the Hellenic subduction zone and numerical simulations of historical tsunamis in the Eastern Mediterranean”, Tectonophysics 536–537, 61–100.
• Yolsal, S., Taymaz, T., and Helvaci, C. 2014. “Earthquake mechanisms in the Gulfs of Gökova, Sığacık, Kuşadası, and the Simav Region (western Turkey): Neotectonics, seismotectonics and geodynamic implications”, Tectonophysics, 635, 100–124.
• Zhao, Y.Z., Wu, Z.L. 2008. “Mapping the b-values along the Longmenshan fault zone before and after the 12 May 2008, Wenchuan, China, Ms 8.0 earthquake”. Natural Hazards and Earth System Sciences 8, 1375–1385.