Simulated Annealing Method: A Seismological Application for The Black Sea Basin

Yıl 2020, Cilt: 25 Sayı: 3, 95 - 106, 30.12.2020

Hamdi Alkan Hakan Çınar

Öz

In this study, the current crust and upper mantle structure of the Black Sea Basin and its surroundings have been studied using data of broad-band earthquake stations. P-wave velocity, S-wave velocity, and Vp/Vs ratio (up to 300 km depth) were obtained for each station and they were associated with recent tectonic situation. To calculate the velocities, the P- and S-wave Receiver Functions were performed to the simultaneous inversion by the using Simulated Annealing method. The dataset included more than 400 teleseismic events. According to velocity histograms, while the Lithosphere-Asthenosphere boundary beneath the Eastern Black Sea Basin increased from north to south with a dome-like slope, a flat increase was observed in the Western Black Sea Basin in the same direction. Mean P-wave and S-wave velocities indicate the presence of the continental lithosphere around the Black Sea and its coastal area. According to these results, tectonically, it may be said that there is southward subduction beneath the Pontides.

Benzetilmiş Tavlama Yöntemi: Karadeniz Havzası için Bir Sismolojik Uygulama

Öz

Öz: Bu çalışmada Karadeniz Havza’nın ve civarının güncel kabuk ve üst manto yapısı çalışılmıştır. Bu amaç doğrultusunda, Karadeniz’in çevresinden seçilen geniş-bantlı deprem istasyonlarının telesismik kayıtları kullanılmıştır. Her bir istasyon altı için P-dalgası hızı, S-dalgası hızı ve Vp/Vs oranı (300 km derinliğe kadar) elde edilmiş ve güncel tektonik durum yorumlanmıştır. Hızların hesaplanması için P- ve S-dalgası Alıcı Fonksiyonları Benzetilmiş Tavlama yöntemi vasıtasıyla birleşik ters çözüm işlemine tabi tutulmuştur. Veri seti yaklaşık olarak 400 adet depremi kapsamaktadır. Elde edilen hız histogramlarına göre, Doğu Karadeniz Havzası’nda kuzeyden güneye doğru Litosfer-Astenosfer geçişi kubbe gibi bir eğim ile artmaktayken, Batı Karadeniz Havzası’nda ise aynı doğrultuda daha yassı bir artış gözlemlenmiştir. Ortalama P-dalgası ve S-dalgası hızları Karadeniz Havzası’nın çevresinde kıtasal özellikli bir litosferin varlığını işaret etmektedir. Tüm bu sonuçlara göre, tektonik olarak güneye eğimli bir yitimin var olduğu söylenebilir.

Anahtar Kelimeler

Karadeniz Havzası, Litosferik Yapı, Alıcı Fonksiyonları

Kaynakça

• Alkan, H., Çınar, H., Oreshin, S., & Vinnik, L. (2019). Investigation of the crustal and upper-mantle structure of the eastern Pontides orogenic belt (NE, Turkey): a receiver-function study. Journal of Seismology, 23(3), 473-491. https://doi.org/10.1007/s10950-019-09818-1.
• Artemieva, I. M., & Shulgin, A. (2019). Geodynamics of Anatolia: Lithosphere thermal structure and thickness. Tectonics, 38. https://doi.org/10.1029/2019TC005594.
• Berkhout, A.J. (1977). Least square inverse filtering and wavelet deconvolution. Geophysics, 42, 1369–1383.
• Berteussen, K.A. (1977). Moho depth determinations based on spectral ratio analysis of NORSAR long-period P waves. Physics of the Earth and Planetary Interiors 15, 13–27.
• Biswas, N.N. (1972). Earth-flattening procedure for the propagation of Rayleigh wave. Pure Applied. Geophys., 96, 61–74.
• Chevrot, S., Vinnik, L., & Montagner, J.P. (1999). Global scale analysis of the mantle Pds phases. Journal of Geophysical Research: Solid Earth 104:203–219. doi: 0148- 0227 / 99 / 1999 JB 900087509.0.
• Çınar, H., & Alkan, H., (2016). Crustal S-wave structure beneath Eastern Black Sea Region revealed by Rayleigh-wave group velocities. Journal of Asian Earth Sciences, 115, 273–284. http://dx.doi.org/10.1016/j.jseaes.2015.10.014.
• Diehl, T., Ritter, J.R.R., & CALIXTO Group, (2005). The crustal structure beneath SE Romania from teleseismic receiver functions. Geophysical Journal International, 163, 238–251. doi:10.1111/j.1365-246X.2005.02715.x.
• Entezar-Saadat, V., Motavalli-Anbaran, S-H., Jamasb, A., & Zeyen, H. (2020). A comprehensive lithospheric study of Black Sea using thermal modeling and simultaneous joint 3D inversion of potential field data. Tectonophysics, 779, 228385. https://doi.org/10.1016/j.tecto.2020.228385.
• Eyuboglu, Y., Santosh, M., Yi, K., Tuysuz, N., Korkmaz, S., & Akaryali, E. (2014). The Eastern Black Sea-type volcanogenic massive sulfide deposits: Geochemistry, zircon U–Pb geochronology and an overview of the geodynamics of ore genesis. Ore Geology Reviews, 59, 29–54. https://doi.org/10.1016/j.oregeorev.2013.11.009.
• Farra, V., & Vinnik, L. (2000). Upper mantle stratification by P and S receiver functions. Geophysical Journal International, 141:699–712. https://doi.org/10.1046/j.1365-246x.2000.00118.x.
• Gobarenko, V.S., & Yegorova, T.P. (2010). The Lithosphere Structure and Geodynamics of the West and East Black Sea Basins. Physics of the Solid Earth, 46-6, 507–523. doi:10.1134/S1069351310060054.
• Gobarenko, V.S., Yegorova, T.P., & Stephenson, R. (2015). Local tomography model of the northeastern Black Sea: intra-plate crustal underthrusting. Geological Society, London, Special Publications, 428. http://doi.org/10.1144/SP428.2.
• Haskell, N.A. (1962). Crustal reflection of plane P and SV waves. Journal of Geophysical Research, 67, 4751–4767.
• Kennett, B.L.N., & Engdahl, E.R. (1991). Travel times for global earthquake location and phase identification. Geophysical Journal International, 105, 429–465. https://doi.org/10.1111/j.1365-246X.1991.tb06724.x.
• Lü, Y., Ni, S., Chen, L., & Chen, Q.F. (2017). Pn tomography with Moho depth correction from eastern Europe to western China. Journal Geophys. Res. Solid Earth, 122, 1284–1301. doi:10.1002/2016JB013052.
• Maden, N. (2013). Geothermal structure of the eastern Black Sea basin and the eastern Pontides orogenic belt: implications for subduction polarity of Tethys oceanic lithosphere. Geosci Front, 4:389–398. http://dx.doi.org/10.1016/j.gsf.2013.02.001.
• Metropolis, N., Rosenbluth, M.N., Rosenbluth, A.W., Teller, A.H., & Teller, E. (1953). Equation of state calculations by fast computing machines. Journal Chem. Phys., 21, 1097–1092.
• Mityukov, A.V., Al’mendinger, O.A., Myasoedov, N.K., Nikishin, A.M., & Gaiduk, V.V. (2011). The Sedimentation Model of the Tuapse Trough (Black Sea). Doklady Earth Sciences, 440, 1245–1248. doi: 10.1134/S1028334X11090303.
• Morais, I.M. (2012). Structure of the crust and mantle beneath Iberia and Western Mediterranean from P and S receiver functions and Sks waveforms. (PhD), Universidade De Lisboa, Departamento De Engenharia, Geofisica. Portugal.
• Mosegaard, K., & Vestergaard, P.D. (1991). A simulated annealing approach to seismic model optimization with sparse prior information. Geophys. Prospect., 39:599–611.
• Motavalli-Anbaran, S.H., Zeyen, H., & Jamasb, A. (2016). 3D crustal and lithospheric model of the Arabia–Eurasia collision zone. Journal Asian Earth Sci., 122, 158–167. http://dx.doi.org/10.1016/j.jseaes.2016.03.012.
• Oreshin, S.I., Vinnik, L.P., Kiselev, S.G., Rai, S.S., Prakasam, K.S., & Treussov, A.V. (2011). Deep seismic structure of the Indian shield, western Himalaya, Ladakh and Tibet. Earth Planet Sci. Lett., 307:415–429. doi:10.1016/j.epsl.2011.05.016.
• Scott, C.L., Shillington, D.J., Minshull, T.A., Edwards, R.A., Brown, P.J., & White, N.J. (2009). Wide-angle seismic data reveal extensive overpressures in the Eastern Black Sea Basin. Geophysical Journal International, 178 (2), 1145–1163. doi: 10.1111/j.1365-246X.2009.04215.x.
• Shillington, D.,J., Scott, C.L., Minshull, T.A., Edwards, R.A., Brown, P.J., & White, N. (2009). Abrupt transition from magma-starved to magma-rich rifting in the eastern Black Sea. Geology, 37-1, 7–10. doi: 10.1130/G25302A.1.
• Stammler, K. (1993). Seismic handler-programmable multichannel data handler for interactive and automatic processing of seismological analyses. Computational Geosciences, 19(2), 135–140. https://doi.org/10.1016/0098-3004(93)90110-Q.
• Starostenko, V.I., Rusakov, O.M., Pashkevich, I.K., Kutas, R.I., Makarenko, I.B., Legostaeva, O.V., Lebed, T.V., & Savchenko, A. (2015). Heterogeneous structure of the lithosphere in the Black Sea from a multidisciplinary analysis of geophysical fields. Geofizicheskiy zhurnal, 37 (2), 3–28. https://doi.org/10.24028/gzh.0203-3100.v37i2.2015.111298.
• Tezel, T., Shibutani, T., & Kaypak, B. (2013). Crustal thickness of Turkey determined by receiver function, Journal of Asian Earth Sciences 75, 36–45. http://dx.doi.org/10.1016/j.jseaes.2013.06.016.
• Vinnik, L. (1977). Detection of waves converted from P to SV in the mantle. Physics of the Earth and planetary interiors, 15:39–45.
• Vinnik, L. (2019). Receiver Function Seismology. Physics of the Solid Earth, 55- 1, 12–21. doi: 10.1134/S1069351319010130.
• Wessel, P., Smith, W.H.F., Scharroo, R., Luis, J.F., & Wobbe, F. (2013). Generic Mapping Tools: improved version released. EOS Trans AGU, 94:409–410.
• Yanovskaya, T.B., Gobarenko, V.S., & Yegorova, T.P. (2016). Subcrustal Structure of the Black Sea Basin from Seismological Data. Izvestiya, Physics of the Solid Earth, 52, 14–28. doi: 10.1134/S1069351316010109.
• Yegorova, T.P., & Gobarenko, V.S. (2010). Structure of the Earth’s crust and upper mantle of the West- and East-Black Sea Basins revealed from geophysical data and its tectonic implications. Geological Society, London, Special Publications, 340, 23–42. doi:10.1144/SP340.
• Yegorova, T., Gobarenko, V., & Yanovskaya, T., (2013). Lithosphere structure of the Black Sea from 3-D gravity analysis and seismic tomography. Geophysical Journal International, 193 (1), 287–303. doi:10.1093/gji/ggs098.