Implications of 2007’s Earthquake Activity in Eğirdir Lake (SW Anatolia) Based on Moment Tensor Solutions and Inversion of Stress State
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We analyzed the waveforms of the small- to moderate-sized earthquakes that took place in the northern part of the inner Isparta Angle (IA) to retrieve their source parameters and combine these results with the focal mechanism solutions of the larger events that occurred in 2007 in Eğirdir Lake at the apex of IA. In total, source mechanisms of 20 earthquakes within the magnitude range 3.5 < M < 5.0 were calculated using a regional moment tensor inversion technique. The inversion of the focal mechanisms yields an extensional regime with a NNE–SSW (N38°E) trending σ 3 axis. Inversion results are related to a mainly WNW–ESE oriented normal fault beneath Eğirdir Lake. The R value of a NNE–SSW extensional regime is 0.562 showing a triaxial stress state in the region. The current stress regime results from complex subduction processes such as slab pull, slab break-off, roll-back and/or retreating mechanism along the Hellenic and Cyprus arcs and the southwestward extrusion of the Anatolian block since the early Pliocene.
KeywordsMoment Tensor African Plate Triaxial Stress State Moment Tensor Solution Moment Tensor Inversion
The authors would like to thank Elif Tolak Çiftçi and Uğur Mustafa Teoman for their contributions. To improve the manuscript, we would also like to thank to the rewivers. This research was supported by Istanbul University Scientific Research Project (Project No: T-673/30062005). Most of the figures were created using the Generic Mapping Tools (GMT) software prepared by Wessel and Smith (1998).
- Agostini, A., Corti, G., Zeoli, A., and Mulugeta, G. (2009), Evolution, pattern and partitioning of deformation during oblique continental rifting: Inferences from lithospheric-scale centrifuge models, Geochem. Geophysics. Geosyst., 10, Q11015, doi: 10.1029/2009GC002676.
- Altuncu, S., Pınar, A., and Yılmazer, M. (2008), Moment tensor inversion solutions for event 2005 KAS earthquake by using zSacWin software, ORFEUS workshop on Waveform Inversion, 19–20 June 2008, Utrecht University, Netherlands (on internet: http://www.orfeus-eu.org/Announcements/workshop_utrecht/workshop_presentations.html).
- Ambraseys, N. (1988), Engineering seismology, J. Earthq. Eng. and Struct. Dyn. 17, p. 66.Google Scholar
- Barka, A.A., Relinger, R.E., Şaroğlu, F., and Şengör, A.M.C. (1997), The Isparta angle: Its importance in the neotectonics of the eastern Mediterranean region, in O. Pişkin, M. Ergun, M.Y. Savaşçin, and G. Tarcan, eds., International Earth Sciences Colloquium of the Aegean Region, 9–14 October 1995, Izmir-Gulluk, Turkey, Procee., 1, 3–17.Google Scholar
- Bellier, O., Zoback, M., 1995, Recent state of stress change in the Walker Lane zone, western Basin and Range province, United States, Tectonics. 14, 564–593.Google Scholar
- Biryol, C.B., Beck, S.L., Zandt, G., Özacar, A.A. (2010), Segmented African Lithosphere Beneath The Anatolian Region Inferred from Teleseismic P-Wave Tomography, Geophysical Journal International. 184, 1034–1057.Google Scholar
- Blumenthal, M. (1963), Le systeme structural du Taurus sud-anatolien. In Livre a memorie du Professeur P. Fallot, Memoire de la Societe Geologique de France. 2, 611–662.Google Scholar
- Boray, A., Saroglu, F. and Emre, O. (1985), Some data regarding E-W contraction in the northern part of the Isparta Angle (in Turkish), Journal of Geology. 23, 9–20.Google Scholar
- Bozkurt, E. (2001), Neotectonics of Turkey-a synthesis, Geodinamica acta. 14, 3–30.Google Scholar
- Brunn, J.H. (1976), L’arc concave zagro-taurique et les arcs convexes taurique et egeen: collision et induits, Bulletin Society Geol. France. (7) XVIII, 2, 553–567.Google Scholar
- Carey, E. (1979). Recherche des directions principales de contraintes associées au jeu d’une population de failles, Rev. Géol. Dynam. Géog. Phys. 21, 57–66.Google Scholar
- Carey-Gailhardis, E. and Mercier, J.L. (1987), A numerical method for determining the state of stress using focal mechanisms of earthquake populations, Earth Planet. Sci. Lett. 82, 165–179.Google Scholar
- Dewey, J.F., Hempton, M.R., Kidd, W.S.F., Saroglu, F, and Sengor, A.M.C., (1986), Shortening of continental lithosphere: the Neotectonics of eastern Anatolia-a young collision zone, in: M.P. Coward and A.C. Ries (eds), collisional tectonics, Geol. Soc. London, Sp. Publ., 19, 3–36.Google Scholar
- Dilek, Y., and Altunkaynak, S. (2009), Geochemical and temporal evolution of Cenozoic magmatism in western Turkey: mantle response to collision, slab break-off, and lithospheric tearing in a orogenic belt, Geological Society, Special Publications. London.Google Scholar
- Dreger, D.S. and Langston, C.A. (1995), Moment Tensor Inversion Workshop, an IRIS DMS short course.Google Scholar
- Dreger, D.S. (2002), Time-Domain Moment Tensor Inverse Code (TDMT_INVC) Release 1.1, (on internet :http://www.seismo.berkeley.edu/~dreger).
- Dumont, J.F., Gutnic, M., Monod, O., and Poisson, A. (1979), Le Trias des Taurides occidentales (Turquie), Definition du bassin Pamphylien: un noveau domain a ophiolites a la marge externe de la chaine taurique, Z. Dtsch. Geol. Ges. 123, 385–409.Google Scholar
- Elitok, O., Özgür, N., Druppel, K., Dilek, Y., Platevoet, B., Guillou, H, Poisson, A., Scailet, S., Satır, M., Siebel, W.,Bardintzeff, J.M.,Deniel, C., Yılmaz, K., (2010), Origin and geodynamic evolution of late Cenozoic potassium-rich volcanism in the Isparta area, southwestern Turkey, International Geology Review, 52, 4–6, 454–504.Google Scholar
- Emre, Ö. (2009), Active fault geometry and recent tectonic in the western of Turkey (in Turkish), 62. Geology Congress of Turkey, MTA, Ankara, Turkey.Google Scholar
- Erduran, M., Endrun, B., and Meier, T. (2008), Continental vs. oceanic lithosphere beneath the eastern Mediterranean Sea—implications from Rayleigh wave dispersion measurement, Tectonophysics. 48, 42–52.Google Scholar
- Faccenna, C., Bellier, O., Martinod, J., Piromallo, C., and Rigard, V. (2006), Slab detachment beneath eastern Anatolia: A possible cause for the formation of the North Anatolian fault, Earth and Planetary Sci. Lett. 242, 85–97.Google Scholar
- Faccenna, C., and Becker, T. W. (2010), Shaping mobile belts by small-scale convection, Nature. 465, 602–605.Google Scholar
- Gans, C.R., Beck, S.L., Zandt, G., Biryol, C.B., and Ozacar, A.A. (2009), Detecting the limit of slab break-off in Central Turkey: New high-resolution Pn tomography results, Geophys. J. Int. 179, 1566–1572.Google Scholar
- Glover, C., and Robertson, A. (1998), Neotectonic intersection of the Aegean and Cyprus tectonic arcs: extensional and strike-slip faulting in the Isparta Angle, SW Turkey, Tectonophysics. 298, 103–132.Google Scholar
- Göğüş, O. H., and Pysklywec, R. N. (2008), Mantle lithosphere delamination driving plateau uplift and synconvergent extension in eastern Anatolia, Geology. 36, no. 9, 723–726, doi: 10.1130/G2498A.1.
- Göğüş, O. H., Pysklywec, R. N., Corbi, F., and Faccenna, C. (2011), The surface tectonics of mantle lithosphere delamination following ocean lithosphere subduction: ınsights from physical scaled analogue experiments, G-cubed, (Geochemistry. Geophysics, Geosystems) in press.Google Scholar
- Jolivet, L., and Faccenna, C. (2000), Mediterranean extension and the Africa–Eurasia collision Tectonics. 19, 1095–1106.Google Scholar
- Jolivet, L. (2001), A comparison of geodetic and finite strain pattern in the Aegean, geodynamic implications, Earth Planet. Sci. Lett. 187, 95–104.Google Scholar
- Kalafat, D., Gurbuz, C., and Ucer, S.B. (1987), Investigation of the structure of crust and upper mantle in western Turkey (in Turkish with English abstract), Earthquake Research Bulletin. 59, 43–64.Google Scholar
- Kalafat, D., Kekovalı, K., Öcal, M., Gülen, L. (2009). Moment Tensor Catalogue of Important Earthquakes in Turkey and Surrounding Regions, American Geophysical Union, Fall Meeting 2009, Abstract ID#ED23A-0536, San Francisco-USA. (on internet: http://adsabs.harvard.edu/abs/2009AGUFMED23A0536K).
- Kalyoncuoğlu, U.Y., Elitok, O., Dolmaz, M.N., and Anadolu, N.C. (2010), Geophysical and geological imprints of southern Neotethyan subduction between Cyprus and the Isparta Angle, SW Turkey, Journal of Geodynamics. 52, 70–82.Google Scholar
- Mercier, J.L., Delibasis, N., Gautier, A., Jarrige, J.J., Lemeille, F., Philip, H., Sébrier, M. and Sorel, D., 1979, La neotectonique de l’Arc Egeen,Rev. Geol. Dyn. Geogr. Phys. 21, 67–92.Google Scholar
- Mercier J. L., Sorel, D. and Vergely, P., 1989, Extensional tectonic regimes in the Aegean basins during the Cenozoic, Basin Research, 2, 49–71.Google Scholar
- McClusky, S., Balassanian, S., Barka, A., Demir, C., Ergintav, S., Georgiev, I., Gurkan, O, Hamburger, M., Hurst, K., Kahle, H., Kastens, K., Kekelidze, G., King, R., Kotzev, V., Lenk, O., Mahmoud, S., Mishin, A., Nadariye, M., Ouzounis, A., Paradissis, D., Peter, Y., Prilepin, M., Reilinger, R., Sanlı, I., Seeger, H., Tealeb, A., Toksoz, N., and Veis, G. (2000), Global Positioning System constraints on plate motion and deformation in the-eastern Mediterranean: Implications for plate dynamics, Journ. Geophys. Res. 105, 5695–5719.Google Scholar
- Över, S., Pinar, A., Özden, S., Yılmaz, H., Unlügenç, U.C., Kamacı, Z., 2010, Late Cenozoic stress field in the Cameli Basin, SW Turkey, Tectonophysics. 492, 60–72.Google Scholar
- Över, S., Özden, S., Yılmaz, H., Pınar, A., Unlügenç, U.C., Kamacı, Z., (2013a), Plio-Quaternary stress regime in Eşen Çay Basin, SW Turkey. Geological Development of Anatolia and the Easternmost Mediterranean Region. Geological Society of London, London, Special Publications, 372, http://dx.doi.org/10.1144/SP372.19.
- Över, S., Yılmaz, H., Pınar, A., Özden, S., Unlügenç, U.C., Kamacı, Z., (2013b), Plio-Quaternary stress states in Burdur Basin, SW-Turkey, Tectonophysics, 588, 56–68.Google Scholar
- Özden, S., Kavak, K.S., Koçbulut, F., Över, S., and Temiz, H. (2002), 3 Şubat 2002 Çay (Afyon) depremleri. Turkiye Jeoloji Bulteni. Cilt: 45, Sayi: 2, sayfa: 49–56.Google Scholar
- Özeren, M.S., and Holt, W. (2010), The dynamics of the eastern Mediterranean and eastern Turkey. Geophysical Journal International. 183, 1165–1184.Google Scholar
- Price S., and Scott B. (1994), Fault block rotations at the edge of a zone of continental extension: southwest Turkey, J. Struct. Geol. 16, 381–392.Google Scholar
- Shaw, B., and Jackson, J. (2010), Earthquake mechanisms and active tectonics of the Hellenic subduction zone, Geophysical Journal International, 181, 966–984.Google Scholar
- Spakman, W., and Hall, R. (2010), Surface deformation and slab–mantle interaction during Banda arc subduction rollback, Nature Geoscience, 3, 562–566, doi: 10.1038/ngeo917.
- Şaroğlu, F., Emre, Ö., and Kuşçu, I. (1992), Active Fault Map of Turkey, General Directorate of Mineral Research and Exploration.Google Scholar
- Şengör, A.M.C. (1980), Principles of Turkey’s neotectonics, Geological Congress of Turkey Conference Series (in Turkish), 2:40.Google Scholar
- Şengör, A.M.C. and Yılmaz, Y. (1981), Tethyan evolution of Turkey: a plate tectonic approach, Tectonophysics. 75, 181–241.Google Scholar
- Şengör, A.M.C., Görür, N., and Şaroğlu, F. (1985), Strike slip faulting and related basi formation in zones of tectonic escape: Turkey as case study, The Society of Economic Paleontologists and Mineralogists. 37, 226–264.Google Scholar
- Taymaz T. and Price S.P. (1992), The 12.05.1971. Burdur earthquake sequence: a synthesis of seismological and geological observations, Geophys. J. Int.108, 589–603.Google Scholar
- Tezel, T., Shibutani, T., and Kaypak, B. (2010), Crustal structure variation in western Turkey inferred from the receiver function analysis, Tectonophysics, 492, 240–252.Google Scholar
- Wessel, P., and Smith, W.H.F. (1998), New improved version of Generic mapping tools released, EOS, Trans. Am. Geophy. Un. 79, 579.Google Scholar
- Yağmurlu, F., Savaşcın, Y., and Ergun, M. (1997), Relation of alkaline volcanism and active tectonism within the evolution of the Isparta Angle, SW Turkey, Journal of Geology. 105, 717–728.Google Scholar
- Yılmazer, M. (2003), Online determination of earthquake source parameters using a new software zSacWin, MSc Thesis, University of Istanbul, Istanbul-Turkey, (in Turkish).Google Scholar