P ve S Alıcı Fonksiyonlarının Birleşik Ters Çözümü: Van Gölü Havzası Örneği

Yıl 2018, Cilt: 23 Sayı: 3, 231 - 242, 11.12.2018

Hamdi Alkan Hakan Çınar

Öz

Bu çalışmada, Van Gölü Havzası’nda bulunan Kandilli Rasathanesi ve Deprem Araştırma Enstiüsü tarafından işletilen AKDM ve MLAZ geniş-bantlı deprem istasyonlarının verileri kullanılarak, P- ve S-Alıcı Fonksiyonlarının Birleşik Ters Çözümü’nden P- ve S-dalgası hız histogramları elde edilmiştir. Ps dönüşüm fazları derinlik-yığma sonuçlarında ve Sp dönüşüm fazları da yavaşlık-yığma sonuçlarında belirlenmiştir. Birleşik ters çözüm sonuçlarına göre, alt kabukta ortalama S dalgası hızları, P dalgası hızları ve Vp/Vs oranı sırasıyla ortalama 3.6 km/sn, 6.3 km/sn ve 1.80’ dir. Düşük hızlar, bölgedeki yaygın volkanizma ve Vp/Vs oranı ise mafik kayaçlar ile ilişkilendirilebilir. MLAZ istasyonu için elde edilen kabuk kalınlığı yaklaşık olarak 42 km iken (Vs 3.6 km/sn’ den 4.3 km/s’ ye ve Vp 6.3 km/sn’ den 7.9 km/s’ ye artmaktadır), AKDM istasyonu için elde edilen kabuk kalınlığı 39 km’ dir (Vs 3.7 km/sn’ den 4.1 km/s’ ye ve Vp 6.4 km/sn’ den 8.1 km/s’ ye artmaktadır). Üst mantoda ~90 km’ ye kadar S-dalgası hızı oldukça düşük olarak elde edilmiştir. Sonuç olarak, üst manto hızları sıcak, sığ astenosferik materyalden dolayı düşüktür.

Anahtar Kelimeler

Van Gölü Havzası, Kabuk ve Üst-Manto Yapısı, P ve S Dalgası Alıcı Fonksiyonları, Birleşik Ters Çözüm

Kaynakça

• Akıncı, A, Antonioli, A., 2012. Observations and stochastic modelling of strong ground motions for the 2011 October 23 M w =7.1 Van, Turkey, earthquake. Geophys. J. Int., 192: 1271-1239.
• Çınar, H., Alkan, H., 2016. Crustal S-wave structure around the Lake Van region (eastern Turkey) from interstation Rayleigh wave phase velocity analyses. Turkish J Earth Sci., 26: 73-90.
• Al-Lazki, A., Sandvol, E., Seber, D., Barazangi, M., Türkelli, N., Mohamad, R., 2004. Pn tomographic imaging of mantle lid velocity and anisotropy at the junction of the Arabian, Eurasian and African Plates. Geophys J Int, 158: 1024-1040.
• Angus, D., Wilson, D., Sandvol, E., Ni, J.F., 2006. Lithospheric structure of the Arabian and Eurasian collision zone in eastern Turkey from S-wave receiver functions. Geophys J Int, 166: 1335-1346.
• Ateş, A., Bilim, F., Büyüksaraç, A., Aydemir, A., Bektaş, Ö., Aslan, Y., 2012. Crustal structure of Turkey from aeromagnetic, gravity and deep seismic reflection data. Surv Geophys, 33: 869-885.
• Barazangi, M., Sandvol, E., Seber, D., 2006. Structure and tectonic evolution of the Anatolian Plateau in eastern Turkey. Geol. Soc. Am., 409: 463-473.
• Bayrak, Y., Yadav, R.B.S., Kalafat, D., Tsapanos, T.M., Çınar, H., Singh, A.P., Bayrak, E., Yılmaz, Ş., Öcal, F., Koravos, G., 2013. Seismogenesis and earthquake triggering during the Van (Turkey) 2011 seismic sequence. Tectonophysics, 601: 163-176.
• Bektaş, Ö., Ravat, D., Büyüksaraç, A., Bilim, F., Ateş, A., 2007. Regional Geothermal Characterisation of East Anatolia from Aeromagnetic, Heat Flow and Gravity Data. Pure appl. Geophysc. 164:975-998.
• 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. Phys. Earth Planet. Int., 15, 13–27.
• Christensen, N.I., 1996. Poisson’s ratio and crustal seismology, Journal of Geophysical Research. 101, 3139-3156.
• Biswas, N.N., 1972. Earth-flattening procedure for the propagation of Rayleigh wave. Pure and Applied Geophysics, 96, 61–74.
• Çukur, D., Krastel, S., Demirel-Schlüter, F., Demirbağ, E., Imren, C., Niessen, F., Toker, M., Paleo-Van Working Group, 2013. Sedimentary evolution of the Lake Van (Eastern Turkey) reconstructed from high-resolution seismic investigations. Int J Earth Sci, 102: 571-585.
• Çukur, D., Krastel, S., Tomonaga, Y., Schmincke, H.U., Sumita, M., Meydan, A.F., Çağatay, M.N., Toker, m., Kim, S.P., kong, G.S., and H, S., 2017. Structural characteristics of the Lake Van Basin, eastern Turkey, from high-resolution seismic reflection profiles and multibeam echosounder data: geologic and tectonic implications. Int J Earth Sci (Geol Rundsch), 106:239–253.
• Delph, J.R., Zandt, G., Beck, S.L., 2015. A new approach to obtaining a 3D shear wave velocity model of the crust and upper mantle: An application to eastern Turkey. Tectonophysics, 665, 92–100.
• Dewey, J.F., Hemton, M.R., Kidd, W.S.F., Saroğlu, F., Şengör, A.M.C., 1986. Shortening of continental lithosphere: the neotectonics of Eastern Anatolia-a young collision zone. In: Coward MP, Ries AC, editors. Collision Tectonics. London, UK: Geology Society of London Special Publications, pp. 3-36.
• Farra, V., Vinnik, L., 2000. Upper mantle stratification by P and S receiver functions. Geophys J. Int., 141, 699-712.
• Gök, R., Pasyanos, M.E., Zor, E., 2007. Lithospheric structure of the continent-continent collision zone: eastern Turkey. Geophys J Int., 169: 1079-1088.
• Gökalp, H., 2012. Tomographic imaging of the seismic structure beneath the East Anatolian Plateau, Eastern Turkey. Pure Appl Geophys, 169: 1749-1776.
• Haskell, N.A., 1962. Crustal reflection of plane P and SV waves. J. Geophys.Res., 67, 4751–4767.
• Keskin, M., 2003. Magma generation by slab steepening and breakoff beneath a subduction-accretion complex: an alternative model for collision-related volcanism in Eastern Anatolia. Turkey.Geophys Res Lett, 30: 8046.
• Kiselev, S., Vinnik, L., Oreshin, S., Gupta, S., Rai, S.S., Singh, A., Kumar, M.R., Mohan, G., 2008. Lithosphere of the Dharwar craton by joint inversion of P and S receiver functions. Geophys. J. Int., 173, 1106-1118.
• Kosarev, G.L., Oreshin, S.I., Vinnik, L.P., Kiselev, S.G., Dattatrayam, R.S., Suresh, G. ve Baidya, P.R., 2013. Heterogeneous lithosphere and the underlying mantle of the Indian subcontinent. Tectonophysics, 592,175–186.
• Metropolis, N., Rosenbluth, M.N., Rosenbluth, A.W., Teller, A.H., Teller, E., 1953. Equation of state calculations by fast computing machines. J. Chem. Phys., 21, 1097–1092.
• Morais, l., Vinnik, L., Silveira, G., Kiselev, S., Matias, L., 2015. Mantle beneath the Gibraltar Arc from receiver functions. Geophys. J. Int., 200, 1153–1169.
• Mosegaard, K., Vestergaard, P.D., 1991. A simulated annealing approach to seismic model optimization with sparse prior information. Geophys.Prospect., 39, 599–611.
• Mosegaard, K., Tarantola, A., 1995. Monte Carlo sampling of solutions to inverse problems. Journal of Geophysical Research, 100, 431-447.
• Mutlu, A.K., Karabulut, H., 2011. Anisotropic Pn tomography of Turkey and adjacent regions. Geophys. J. Int., 187: 1743-1758.
• 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 and Planetary Science Letters, 307, 415–429.
• Oruç, B., Ortiz, D.G., Petit, C., 2017. Lithospheric flexural strength and effective elastic thicknesses of the Eastern Anatolia (Turkey) and surrounding region. Journal of Asian Earth Sciences, 150, 1–13.
• Özacar, A.A., Zandt, G., Gilbert, H., Beck, S.L., 2010. Seismic images of crustal variations beneath the East Anatolian Plateau (Turkey) from teleseismic receiver functions. Geo Soc. S. P., 340: 485-496.
• Silveira, G., Vinnik, L., Stutzmann, E., Kiselev, S., Farra, V., Morais, I., 2010. Stratification of the Earth beneath the Azores 1 from P and S receiver functions. Earth Planet. Sci. Lett., 229, 91-103.
• Sandvol, E., Türkelli, N., Barazangi, M., 2003. Eastern Turkey seismic experiment: the study of a young continent–continent collision. Geophys Res Lett, 30: 8038.
• Skobeltsyn, G., Mellors, R., Gök, R., Türkelli, N., Yetirmishli, G., Sandvol, E., 2014. The upper mantle S wave velocity structure of the East Anatolian-Caucasus region. Tectonics 33: 207-221.
• Şengör, A.M.C., Yılmaz, Y., 1981. Tethyan evolution of Turkey: a plate tectonic approach. Tectonophysics, 75: 181-241.
• Şengör, A.M.C., Özeren, S., Genç, T., Zor, E., 2003. The East Anatolian High Plateau as a mantle-supported, north-south shortened domal structure. Geophys Res Lett, 30: 8045.
• Tezel, T., Shibutani, T., Kaypak, B., 2013. Crustal thickness of Turkey determined by receiver function. J Asian Earth Sci, 75: 36-45.
• Vanacore, E.A., Taymaz, T., Saygın, E., 2013. Moho structure of the Anatolian Plate from receiver function analysis. Geophys J Int, 193: 329-337.
• Vinnik, L.P., 1977. Detection of waves converted from P to SV in the mantle. Phys, Earth Planet. Inter., 583, 15, 3945.
• Vinnik, L.P., Roecker, S., Kosarev, G.L., Oreshin, S.I., Koulakov, Y.I., 2002. Crustal structure and dynamics of the Tien Shan. Geophysical Research Letters, 29, 2047. Vinnik, L., Aleshin, I.M., Kaban, M.K., Kiselev, S.G., Kosarev, G.L., Oreshin, S.I., Reigber, Ch., 2006. Crust and mantle of Tien Shan from Data of the receiver Function Tomography. Phys, Solid Earth, 42, 8, 639–651.
• Vinnik, L., Farra, V., 2007. Low S velocity atop the 410-km discontinuity and mantle plumes. Earth Planet. Sci. Lett., 262, 398-412.
• 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.
• Zhu, H., 2018. High Vp/Vs ratio in the crust and uppermost mantle beneath volcanoes in the Central and Eastern Anatolia, Geophys. J. Int. 214, 2151–2163.
• Zor, E., Sandvol, E., Gürbüz, C., Türkelli, N., Seber, D., Barazangi, M., 2003. The crustal structure of the Eastern Anatolian Plateau (Turkey) from receiver functions. Geophys Res Lett, 30: 8044.
• Zor, E., 2008. Tomographic evidence of slab detachment beneath eastern Turkey and the Caucasus. Geophys. J. Int., 175: 12731282.