P-Alıcı Fonksiyonları ve Rayleigh Dalgası Grup Hızları’nın Birleşik Ters Çözümü’nden Doğu Anadolu Fay Zonu’nun Kabuk ve Üst Manto Hız Yapısı

Öz

Geçmişten günümüze, yoğun depremselliğin meydana geldiği Doğu Anadolu Fay Zonu (DAFZ) aktif bir plaka sınırıdır. Bu aktivite bölgenin jeodinamik yapısı ile kesinlikle ilişkilidir. Arap plakasının kuzeye ve Avrasya plakasının güneye hareketinden dolayı, Anadolu plakası saat yönünün tersi doğrultusunda batıya doğru kaçmaya teşebbüs etmektedir. Bu tektonik hareket, önemli tektonik yapıların gelişmesine sebep olmaktadır. Aktif plaka hareketleriyle ilişkili olarak, kuzey-doğuda Kuzey Anadolu Fayı ve güney-batıda Ölü Deniz Fayı ile kesişen Doğu Anadolu Fayı’nın S-dalgası hız yapısı bölgenin tektonik yapısını yorumlamada oldukça önemlidir. Bu çalışmada DAFZ boyunca sekiz adet geniş-bantlı deprem istasyonundan toplanan verilerin kullanılmasıyla, P-Alıcı Fonksiyonu ve Rayleigh dalgası grup hızı birleşik ters çözümü yöntemi uygulanmıştır. P-Alıcı fonksiyonları 3-bileşen geniş-bantlı sismometreler de kayıt edilen ve her istasyon için ayrı ayrı yaklaşık 80 adet tele-sismik depremin kullanılmasıyla elde edilmiştir. Diğer taraftan, Rayleigh dalgası grup hızı dispersiyon eğrileri için odak derinliği 50 km’den küçük ve moment magnitüdü 5.0’dan büyük 21 lokal deprem kullanılmıştır. Her istasyon için bu iki yöntemden elde edilen sonuçlar, kabuk ve üst-mantonun 1-Boyutlu S-dalgası hız yapısını belirlemek için birlikte ters çözüm işlemine tabii tutulmuştur. DAFZ boyunca, S-dalgası hız modelleri üst kabukta yani yaklaşık olarak 4-12 km derinliklerinde, düşük hızlı tabakaların varlığını göstermektedir. Bununla birlikte, istasyonlar boyunca Conrad süreksizliği 22 km derinliği civarındadır. Ayrıca, kabuk-manto geçişi yaklaşık olarak ~44 km derinliğindedir. Sonuç olarak, bu çalışma, incelenen bölgenin tektoniği ile uyumlu kabuk ve en üst manto S-dalgası hız yapısını ortaya koymaktadır.

Anahtar Kelimeler

• Alıcı Fonksiyonları
• Rayleigh Dalgası Dispersiyonu
• Birleşik Ters Çözüm
• Kabuk Yapısı
• Kesme Dalgası Hızı
• Doğu Anadolu Fay Zonu

Crust and Uppermost Mantle Velocity Structure beneath Eastern Anatolian Fault Zone from Joint Inversion of P-Receiver Functions and Rayleigh Wave Group Velocities

Öz

The Eastern Anatolian Fault Zone (EAFZ) is an active plate boundary where intense seismicity has occurred from past to present. This activity is related to the geodynamic structure of the region. Because of the Arabian plate northward motion and the Eurasian plate southward motion, the Anatolian plate has attempted to escape westward with anticlockwise rotation, caused the development of important tectonic structures. Concerning these active plate motions, the S-wave velocity structure of EAFZ intersecting the North Anatolian Fault Zone (NAFZ) in the northeast and the Dead Sea Fault Zone (DSFZ) in the southwest is important in interpreting the tectonics of region. The present study is conducted on the joint inversion of P-wave receiver functions and Rayleigh wave group velocities techniques using the data collected from eight broadband stations along the EAFZ. The P-receiver functions are analyzed using approximately eighty teleseismic events for each station, recorded by the three-component broadband seismometers. On the other hand, for the Rayleigh wave group velocity dispersion curves calculations twenty-one regional earthquakes are used, which have focal depth less than 50 km and bigger than moment magnitude Mw=5.0. The analyses obtained from these two techniques is jointly inverted to determine the 1-D S-wave velocity structure of crust and uppermost mantle for each station. The results of inversion indicate that the S-wave velocity models show that the low-velocity layers are identified within the approximately 4-12 km in the upper crust. Besides, the Conrad discontinuity is determined as the depth of ~22 km along with the seismic stations. Furthermore, the crust-mantle boundary is ~44 km depth along with the EAFZ. Consequently, this study yields the crustal and uppermost mantle S-wave velocity structure compatible with the regional tectonics of the studied region.

Anahtar Kelimeler

• Receiver Functions
• Rayleigh Wave Dispersion
• Joint Inversion
• Crustal Structure
• Shear Wave Velocity
• Eastern Anatolian Fault Zone

Kaynakça

1. Abdul Latiff, A.H., Khalil, A.E. (2019). Crustal thickness and velocity structure of Malay Peninsula inferred from joint inversion of receiver functions and surface waves dispersion. Journal of Asian Earth Sciences, 169, 105–116.
2. Agrawal, M, Pulliam, J., Sen, M.K., Dutta, U., Pasyanos, M.E., Mellors, R. (2015a). Crustal and uppermost mantle structure in the Middle East: assessing constraints provided by jointly modelling Ps and Sp receiver functions and Rayleigh wave group velocity dispersion curves. Geophys. J. Int., 201, 783–810.
3. Agrawal, M., Pulliam, J., Sen, M.K., Gurrola, H. (2015). Lithospheric structure of the Texas-Gulf of Mexicpassive margin from surface wave dispersion and migrated Ps receiver functions. Geochem. Geophys. Geosyst.,16, 2221–2239.
4. Akpan, O., Nyblade, A., Okereke, C., Oden, M., Emry, E., Julià, J. (2016). Crustal structure of Nigeria and Southern Ghana, West Africa from P-wave receiver functions. Tectonophysics, 676, 250–260.
5. 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. Geophysical Journal International, 158, 1024–1040.
6. Ammirati, J.B., Patricia, A., Beck, S. (2015). A lithospheric velocity model for the flat slab region of Argentina from joint inversion of Rayleigh wave phase velocity dispersion and teleseismic receiver functions. Geophys. J. Int., 202, 224–241.
7. Ammon, C.J., Randall, G.E., Zandt, G. (1990). On the non-uniqueness of receiver function inversions. J. Geophys. Res., 95, 15303–15318.
8. Andriampenomanana, F., Nyblade, A.A., Wysession, M.E., Durrheim, R.J., Tilmann, F., Julia, J., Pratt, M.J., Rambolamanana, G., Aleqabi, G., Shore, P.J., Rakotondraibe, T. (2017). The structure of the crust and uppermost mantle beneath Madagascar. Geophys. J. Int., 210, 1525–1544.

9. 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. Geophysical Journal International., 166, 1335–1346.
10. Badawy, A., Hegazi, M., Gaber, H., Korrat, I. (2018). Crustal structure of northern Egypt from joint inversion of receiver functions and surface wave dispersion velocities. J Seismol, 22, 697-719.
11. Bakirci, T., Yoshizawa, K., Ozer, M.F. (2012). Three-dimensional S-wave structure of the upper mantle beneath Turkey from surface wave tomography. Geophysical Journal International., 190(2), 1058–1076.
12. 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 and Applied Geophysics., 164, 975–998.
13. Bozkurt, E. (2001). Neotectonics of Turkey-a synthesis. Geodyn Acta., 14, 3–30.
14. Cheloni, D., Akinci, A. (2020). Source modelling and strong ground motion simulations for the 24 January 2020, Mw 6.8 Elazığ earthquake, Turkey. Geophys. J. Int., 223, 1054–1068.
15. Çoban, K.H., Sayıl, N. (2020). Different probabilistic models for earthquake occurrences along the North and East Anatolian fault zones. Arabian Journal of Geosciences, 13, 971.
16. Çınar, H., Alkan, H. (2017). 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.
17. Çırmık, A. (2018). Examining the crustal structures of Eastern Anatolia, using thermal gradient, heat flow, radiogenic heat production and seismic velocities (Vp and Vs) derived from Curie point depth. Bollettino di Geofi sica Teorica ed Applicata, 59(2), 117–134.
18. 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.
19. Desphande, A.A., Mohan, G. (2016). Seismic evidence of crustal heterogeneity beneath the Northwestern Deccan volcanic province of India from joint inversion of Rayleigh wave dispersion measurements and P receiver functions. Journal of Asian Earth Sciences, 128, 54–63.
20. Dewey, J.F., Hempton, M.R., Kidd, W.S.F., Saroglu, F., Sengor, A.M.C. (1986). Shortening of continental lithosphere: The neo-tectonics of eastern Anatolia-a young collision zone. In M. P. Coward and A. C. Reis (Eds.), Collision tectonics, (3–36). London: Geological Society.
21. Dziewonski, A., Bloch, S., Landisman, M. (1969). A technique for the analysis of transient seismic signals. Bull. Seismol. Soc. Am., 1, 427–444.
22. Gilligan, A., Roecker, S.W., Priestley, K.F., Nunn, C. (2014). Shear velocity model for the Kyrgyz Tien Shan from joint inversion of receiver function and surface wave data. Geophys. J. Int., 199, 480–498.
23. Goforth, T., Herrin, E. (1979). Phase-matched filters: application to study of Love waves. Bull. Seismol. Soc. Am., 69, 27–44.
24. Gonzalez, O.L., Moreno, B., Romanelli, F., Panza, G.F. (2012). Lithospheric structure below seismic stations in Cuba from the joint inversion of Rayleigh surface waves dispersion and receiver functions. Geophys. Journal Int., 1-13.
25. Gökalp, H. (2012). Tomographic imaging of the seismic structure beneath the East Anatolian Plateau. Eastern Turkey Pure Appl Geophys., 169, 1749-1776.
26. Helffrich, G., Wookey, J., Bastow, I. (2013). The Seismic Analysis Code, A Primer and User’s Guide. Cambridge. United Kingdom.
27. Herrmann, R.B., Ammon, C.J. (2002). Computer program in seismology: surface waves, receiver functions and crustal structure. In: S.L. University (Editor).
28. Herrmann, R.B. (2013). Computer programs in seismology: an evolving tool for instruction and research. Seismol. Res. Lett., 84, 1081–1088.
29. Jamalreyhani, M., Büyükakpınar, P., Cesca, S., Dahm, T., Sudhaus, H., Rezapour, M., Isken, M.P., Asayesh, B.M., Heimann, S. (2020). Seismicity related to the eastern sector of Anatolian escape tectonic: the example of the 24 January 2020 Mw 6.77 Elazığ-Sivrice earthquake. Solid Earth, https://doi.org/10.5194/se-2020-55.
30. Julia, J., Ammon, C.J., Herrmann, R.B., Correig, A.M. (2000). Joint inversion of receiver function and surface wave dispersion observations. Geophys. J. Int., 143, 99–112.
31. Kennett, B.L.N., Engdahl, E.R., Buland, R. (1995). Constraints on seismic velocities in the Earth from traveltimes, Geophys. J. Int., 122, 108–124.
32. Kind, R., Eken, T., Tilmann, F., Sodoudi, F., Taymaz, T., Bulut, F., et al. (2015). Thickness of the lithosphere beneath Turkey and surroundings from S-receiver functions. Solid Earth, 6, 971–984.
33. Langston, C.A. (1977). Corvallis, oregon, crustal and upper mantle receiver structure from teleseismic P and S waves. Bullet. Seismol. Soc. Am., 67(3), 713–724.
34. Ligorria, J.P., Ammon, C.J. (1999). Iterative deconvolution and receiver function estimation. Bullet. Seismol. Soc. Am., 89(5), 1395–1400.
35. Lü, Y.S., Ni, L., Chen, Q.F. (2017). Pn tomography with Moho depth correction from eastern Europe to western China. J Geophys Res. Solid Earth, 122, 1284–1301.
36. Mahatsente, R., Önal, G., Çemen, I. (2018). Lithospheric structure and the isostatic state of Eastern Anatolia: Insight from gravity data modelling. Lithosphere, 10(2), 279–290.
37. McClusky, S., Balassanian, S., Barka, A., Demir, C., Ergintav, Georgiev, I., et al. (2000). Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. Journal of Geophysical Research, 105, 5695–5719.
38. Melgar, D., Ganas, A., Taymaz, T., Valkaniotis, S., Crowell, B.W., Kapetanidis, V., Tsironi,V., Yolsal-Çevikbilen, S., Öcalan, T. (2020). Rupture kinematics of 2020 January 24 Mw 6.7 Doğanyol-Sivrice, Turkey earthquake on the East Anatolian Fault Zone imaged by space geodesy. Geophys. J. Int., 223, 862–874.
39. Motavalli-Anbaran, S.H., Zeyen, H., Jamasb, A. (2016). 3D crustal and lithospheric model of the Arabia–Eurasia collision zone. J. Asian Earth Sci., 122, 158–167.
40. Oruç, B., Gomez-Ortiz, D., Petit, C. (2017). Lithospheric flexural strength and effective elastic thicknesses of the Eastern Anatolia (Turkey) and surrounding region. J Asian Earth Sci., 150, 1–13.
41. Ozer, C., Ozyaziciglu, M., Gök, E., Polat O. (2019). Imaging the Crustal Structure Throughout the East Anatolian Fault Zone, Turkey, by Local Earthquake Tomography. Pure Appl. Geophys., 176, 2235–2261.
42. 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. Geology Society London Special Publications, 340, 485–496.
43. Öztürk, S. (2018). Earthquake hazard potential in the Eastern Anatolian Region of Turkey: seismotectonic b and Dc-values and precursory quiescence Z-value. Front. Earth Sci., 12(1), 215–236.
44. Pasyanos, M.E., Masters, T.G., Laske, G., Ma, Z. (2014). LITHO1.0: An updated crust and lithospheric model of the Earth. J. Geophys. Res. Solid Earth, 119, 2155-2173.
45. Reilinger, R., McClusky, S., Vernant, P., Lawrence, S., Ergintav, S., Cakmak, R., et al. (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, Solid Earth, 111(B5), B05411.
46. Salah, M.K., Şahin, Ş. (2019). 3D crustal velocity and Vp/Vs structures beneath Southeast Anatolia and their geodynamic implications. Геофизический журнал, 2, 41.
47. Şengör, A.M.C., Yılmaz, Y. (1981). Tethyan evolution of Turkey: a plate tectonic approach. Tectonophysics, 75, 181–241.
48. Şengör, A.M.C., Görür, N., Şaroğlu, F. (1985). Strikeslip faulting and related basin formation in zones of tectonic escape Turkey as a case study. In: Biddle, K.T., Christie-Blick, K. (Eds.), Strike-slip Deformation Basin Formation and Sedimentation. Soc. Econ. Paleontol. Miner. Spec. Publ., 37, 227–264.
49. Tezel, T., Shibutani, T., Kaypak, B. (2013). Crustal thickness of Turkey determined by receiver function. Journal of Asian Earth Sciences, 75, 36–45.
50. Türkoğlu, E., Unsworth, M., Bulut, F., Çağlar, I. (2015). Crustal structure of the North Anatolian and East Anatolian Fault Systems from magnetotelluric data. Physics of the Earth and Planetary Interiors, 241, 1–14.
51. Vanacore, E. A., Taymaz, T., Saygin, E. (2013). Moho structure of the Anatolian plate from receiver function analysis. Geophysical Journal International, 193(1), 329–337.
52. Vinnik, L. (1977). Detection of waves converted from P to SV in the mantle. Physics of the Earth and Planetary Interiors, 15, 39–45.
53. Warren, L.M., Beck, S.L., Biryol, C.B., Zandt, G., Ozacar, A.A., Yang, Y. (2013). Crustal velocity structure of Central and Eastern Turkey from ambient noise tomography. Geophysical Journal International. 194(3), 1941–1954.
54. 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.
55. Yön, B., Onat, O., Öncü, M.E., Karaşin, A. (2020). Failures of masonry dwelling triggered by East Anatolian Fault earthquakes in Turkey. Soil Dynamics and Earthquake Engineering, 133, 106-126.
56. Zor, E., Sandvol, E., Gurbuz, C., Turkelli, N., Seber, D., Barazangi, M. (2003). The crustal structure of the East Anatolian plateau (Turkey) from receiver functions. Geophysical Research Letters, 30(24), 8044.