Crustal Structure of Eastern Anatolia from Single-Station Rayleigh Wave Group Velocities

Yıl 2015, Cilt: 1 Sayı: 2, 57 - 69, 20.07.2015

Hakan Çınar , Hamdi Alkan

Öz

In this study, crustal structure of the Eastern Anatolia has been obtained by inverting group-velocity dispersion data of fundamental mode Rayleigh waves, using single-station method in the period range of 4-40 seconds approximately. For this purpose, we have used recordings of mainshock and its aftershocks of the 2011 Van Earthquake recorded on KOERI (Kandilli Observatory and Earthquake Research Institute) broad band (BB) stations (ERZN, DARE, GAZ, KMRS, RSDY, SARI, SVRC, SVSK, URFA). The fundamental modes of vertical component broad-band seismograms are isolated to higher modes. 1-D shear velocity structure of the region is obtained from observed fundamental mode group velocity dispersion curves and their inversion results. We have also calculated the normalized statistical resolution matrix to obtain resolution-length information for total inverse system. The Normalized statistical resolution matrix could not only measure the resolution obtainable from the data, but also provided reasonable spatial/temporal resolution or resolution-length information.  

Considering the locations of selected events, we have created three distinct groups and averaged the group velocity dispersion curves. The mean dispersion curves of Rayleigh waves have been inverted to determine shear wave structure represents the study region. According to inversion results, the crustal thickness is approximately 42 km in the study area and Vs velocity ranges between 4.19-4.29 km/s. It is clearly seen that shear velocities vary from ∼2.8–3.2 km/s in the upper crust (10-12 km) to ∼3.5–3.7 km/s in the lower crust (22-24 km). These values are compatible with other studies’ values.

Anahtar Kelimeler

Eastern Anatolia, Crustal Structure

Kaynakça

• AKI, K., and RICHARDS, P.G. (1980), Quantitative seismology. WH Freeman and Company, San Francisco, pp 259–330.
• ALKAN, H., ÇINAR, H., AKKAYA, İ. (2011), Determination of the Crustal Structure in the Eastern Anatolian using Main and After Shocks of the 2011 Van Earthquake, İzmir, TURKEY, 5-7 June.
• AL-LAZKI, AI., SANDVOL, E., SEBER, D., BARAZANGI, M., TURKELLI, N., and MOHAMAD, R. (2004), Pn Tomographic Imaging of Mantle Lid Velocity and Anizotropy at the Junction of the Arabian, Eurasian and African Plates, Geophysical Journal International 158, 1024-1040.
• AN, M., (2012), A simple method for determining the spatial resolution of a general inverse problem. Geophys. J. Int. 191, 849–864.
• ANGUS, D.A., WILSON, D.C., SANDVOL, E., NI, and 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.
• ATES et al. (2012), Crustal Structure of Turkey from Aeromagnetic, Gravity and Deep Seismic Reflection Data. Surv Geophys, 33:869–885.
• BAKIRCI, T., Yoshizawa, K., and ÖZER, K.M. (2012), Three-dimensional S-wave structure of the upper mantle beneath Turkey from surface wave tomography, Geophys. J. Int., 190:1058–1076.
• BARKA, A. and KADINSKY-CADE, K. (1988), Strike-slip fault geometry in Turkey and its influence on earthquake activity. Tectonics 7:663–684
• BAYRAK, Y., ATMIŞ, A., TEMELLİ, F.,MOHAMMADI, H., BAYRAK, E., YILMAZ, Ş., and TÜRKER, T., (2013). An Evaluation of Earthquake Hazard Parameters in and around Ağrı, Eastern Anatolia, Turkey. Eastern Anatolian Journal of Science, 1: 01-09.
• BEKTAS, Ö., RAVAT, D., BUYUKSARAC, A., BILIM, F., and ATES, A. (2007), Regional Geothermal Characterisation of East Anatolia from Aeromagnetic, Heat Flow and Gravity Data. Pure appl. Geophysc 164:975-998.
• BIRYOL, C.B., BECK, S.L., ZANDT, G., and ÖZACAR, A.A. (2011), Segmented African lithosphere beneath the Anatolian region inferred from teleseismic P-wave tomography. Geophys. Jour. Int.
• CAMBAZ, D.M., KARABULUT, H. (2010), Love-wave group velocity maps of Turkey surrounding regions. Geophys. Jour. Int., 181:502–520.
• ÇINAR, H., (1998), Analysis of single station Rayleigh wave recordings of earthquakes in and around the Eastern Anatolia. PhD thesis (in Turkish with English abstract), Karadeniz Technical University, Institute of Science.
• ÇETİNOL, T., and YOSHIZAWA, K. (2007), Surfave WAve Ohase Velocity Distribution of Turkey, İnternational Earthquake symposium, Kocaeli.
• DZIEWONSKI, A., BLOCH, S., and LANDISMAN, M. (1969), A tecnique for the analysis of Transient Seismic Signals. Bulletin of the seismological society of America, Vol. 59, No.1, pp 427-444.
• GOFORTH, T., and HERRIN, E., (1979), Phase-matched filters: application to study of Love waves. Bulletin of the Seismological of America,69, 27-44.
• -
• GÖK, R., PASYANOS, M.E., and ZOR, E., (2007), Lithospheric structure of the continent–continent collision zone: eastern Turkey, Geophys. J. Int., 169:1079–1088.
• GÖK, R., MELLORS, R.J., SANDVOL, E., PASYANOS, M, HAUK, T., TAKEDATSU, R., YETIRMISLI, G., TEOMAN, U., TURKELLI, N., GODOLADZE, T., and JAVAKISHVIRLI, Z. (2011), Lithospheric velocity structure of the Anatolian plateau‐Caucasus‐Caspian region. journal of geophysical research, VOL. 116, B05303, doi:10.1029/2009JB000837.
• -
• GÖKALP, H. (2007), Local earthquake tomography of the Erzincan Basin and the surrounding area in Turkey. Annals of Geophysics, Vol. 50, N:6.
• GÖKALP, H. (2012), Tomographic Imaging of the Seismic Structure Beneath the East Anatolian Plateau, Eastern Turkey. Pure and Applied Geophysics, 1691749–1776.
• HEARN, T.M., and NI, JF. (1994), Pn Velocities beneath Continental Collision Zones: the Turkish-Iranian Plateau. Geophysical Journal International 117, 273-283.
• HERRMANN, R.B., (1991). In: Herrmann, R.B. (Ed). Surface Wave Inversion Program. Saint Louis University, Saint Louis, MO.
• HERRMANN, R. B. (2013), Computer programs in seismology: An evolving tool for instruction and research, Seism. Res. Lettr. 84, 1081-1088, doi:10.1785/0220110096.
• KENNETT, B.L.N., EENGDAHL, E.R. and BULAND, R., (1995), Constraints on seismic velocities in the Earth from travel times. Geophys. J. Int., 122, 108–124.
• LEI, J., and ZHAO, D. (2007), Teleseismic evidence for a break-off subducting slab under Eastern Turkey. Earth and Planetary Science Letters 257:14–28.
• MAGGI, A. and PRIESTLY, K. (2005), Surface waveform tomography of the Turkish–Iranian plateau. Geophys. J. Int.160:1068–1080.
• MARTINEZ, M.D., CANAS, J.A., LANA, X., and BADAL, J. (2001), Objective regionalization of Rayleigh wave dispersion data by clustering algorithms: an aplication to the Mediterranean basin. Tectonophysics, 330, 245-266.
• McCLUSKY, S. et al. (2000), GPS constraints on plate kinematics and dynamics in the Eastern Mediterranean and Caucasus. J Geophys Res 105:5695–5719.
• MINDEVALLI, O.Z. and MITCHELL, B.J. (1989), Crustal structure and possible anisotropy in Turkey from seismic surface wave dispersion, Geoophys. J. Int, 98:93-106.
• MUTLU, A.K. and KARABULUT, H. (2011), Anisotropic Pn tomography of Turkey and adjacent regions, Geophys. Journal International, doi: 10.1111/j.1365-246X.2011.05235.x.
• OLIVER, J. (1962), A Summary of Observed Seismic Surface Wave Dispersion. Bulletin of the Seismological Society of America 1,81-86.
• OZACAR, A.A., GILBERT, H., and Zandt, G. (2008), Upper mantle discontinuity structure beneath East Anatolian Plateau (Turkey) from receiver functions. Earth and Planetary Science Letters 269:427–435.
• OZACAR, A.A., ZANDT, G., GILBERT, H., and SUSAN L. BECK, S.L. (2010), Seismic images of crustal variations beneath the East Anatolian Plateau (Turkey) from teleseismic receiver functions. Geological Society, London, Special Publications, 340, 485–496.
• REILINGER et al. (2006), GPS constraints on continental deformation in the Africa–Arabia–Eurasia continental collision zone and implications for the dynamics of plate interactions. J Geophys Res 111:B05411.
• PASYANOS, M.E., WALTER, W.R., FLANAGAN, M.P., GOLDSTEIN, P. and BHATTACHARYYA, J., (2004), Building and testing an a priori geophysical model for western Eurasia and north Africa. Pure appl. Geophys., 161, 235– 281.
• SANDVOL, E., SEBER, D., CALVERT, A., and BARAZANGİ, M., (1998). Grid search modeling of receiver functions: Implications for crustal structure in the Middle East and North Africa, journal of geophysİcal research, 103:899-917.
• -
• SAYIL, N. (2015), Determination of the Crust and Upper-Mantle Structure in Anatolia by Surface Wave Data, Natural Science, 6:968-977.
• ŞENGÖR A.M.C., GÖRÜR N., and ŞAROĞLU, F. (1985), Strike-slip faulting and related basin formation in zones of tectonic escape: Turkey as a case study. Spec Publ Soc Econ Paleontol Mineral 37:227–264.
• TEZEL, T., ERDURAN, M., and ALPTEKİN, Ö. (2007), Crustal shear wave velocity structure of Turkey by surface wave dispersion analysis. Annals of Geophyscis, 50:177-190.
• TEZEL, T., SHIBUTANİ, T. and KAYPAK, B. (2013), Crustal thickness of Turkey determined by receiver function. Journal of Asian Earth Sciences, 75:36–45.
• UTKUCU, M. (2013), 23 October 2011 Van, Eastern Anatolia, earthquake (Mw 7.1) and seismotectonics of Lake Van area. J Seismol 17:783–805
• VANACORE, E.A., TAYMAZ, T., and SAYGIN, E. (2013), Moho structure of the Anatolian Plate from receiver function analysis. Geophys. J. Int., 193:329–337.
• WARREN, M. L., BECK, S.L., BIRYOL, C.B., ZANDT, G., OZACAR, A.A., and YANG, Y. (2013) Crustal velocity structure of Central and Eastern Turkey from ambient noise tomography. Geophys. J. Int., 194:1941–1954.
• -
• ZOR, E., SANDVOL, E., GURBUZ, C., TURKELLİ, N., SEBER, D.,and BARAZANGI, M. (2003), The crustal structure of the East Anatolian plateau (Turkey) from receiver functions, Geophys. Res. Lett., 30(24), 8044, doi:10.1029/ 2003GL018192.
• ZOR, E. (2008), Tomographic evidence of slab detachment beneath eastern Turkey and the Caucasus. Geophys. J. Int.,175:1273–1282.