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Resistivity structure in the western part of the fault rupture zone associated with the 1999 İzmit earthquake and its seismogenic implication

Abstract

Magnetotelluric (MT) surveys were carried out along some profiles crossing the fault rupture zone associated with the İzmit earthquake which took place on 17 August 1999 in the western part of the North Anatolian Fault Zone (NAFZ). In this paper, we focus on the western part of the fault rupture zone where two different groups of seismicity followed the İzmit earthquake. One group was seen along a narrow belt and corresponds to aftershocks occurring along the fault rupture zone. The other was seen in a circular region and represents a swarm activity, presumably triggered by the occurrence of the İzmit earthquake. Two-dimensional inversion was performed for the MT data acquired along two profiles; one crosses the western end of the fault rupture zone and the other is located in the west of the swarm activity area. In the former case, aftershocks tended to occur in a resistive zone underlain by a moderately conductive zone, as was the case for the hypocenter area. In the latter case, the swarm activity tends to be confined in a conductive zone below a highly resistive zone. This activity is likely to be triggered through pore-pressure changes associated with the İzmit earthquake.

References

  • Barış, S., A. Ito, S. B. Üçer, Y. Honkura, N. Kafadar, R. Pektaş, T. Komut, and A. M. Işıkara, Microearthquake activity before the Izmit earthquake in the eastern Marmara region, Turkey (1 January 1993–17 August 1999), Bull. Seismol. Soc. Am., 92, 394–405, 2002.

    Article  Google Scholar 

  • Bayrak, M. and S. S. Nalbant, Conductive crust imaged in western Turkey by MT, Geophys. Res. Lett., 28(18), 3521–3524, 2001.

    Article  Google Scholar 

  • Çağlar, I., Electrical resistivity structure of the northwestern Anatolia and its tectonic implications for the Sakarya and Bornova zones, Phys. Earth Planet. Inter., 125, 95–110, 2001.

    Article  Google Scholar 

  • Eisonlohr, T., The thermal springs of Armutlu peninsula (NW Turkey) and their relationship to geology and tectonic, in Active Tectonics of Northwestern Anatolia: The Marmara Poly-Project, Edited by C. Shindler and M. Pfister, Cambridge Publications, pp. 197–228, 1996.

    Google Scholar 

  • Gamble, T. D., W. M. Goubau, and J. Clarke, Magnetotellurics with remote magnetic reference, Geophysics, 44, 53–68, 1979.

    Article  Google Scholar 

  • Groom, R. W. and R. C. Bailey, Decomposition of magnetotelluric impedance tensors in the presence of local three dimensional galvanic distortions, J. Geophys. Res., 94, 1913–1925, 1989. Gürer, A., Deep conductivity structure of the North Anatolian Fault Zone and the Istanbul and Sakarya Zones along the Golpazari-Akcakoca profile, Northwest Anatolia, Int. Geology Review, 38, 727–736, 1996.

    Article  Google Scholar 

  • Honkura, Y., A. M. Işikara, N. Oshiman, A. Ito, B. Üçer, S. Bariş, M. K. Tunçer, M. Matsushima, R. Pektaş, C. Çelik, S. B. Tank, F. Takahashi, M. Nakanishi, R. Yoshimura, Y. Ikeda and T. Komut, Preliminary results of multidisciplinary observations before, during and after the Kocaeli (Izmit) earthquake in the western part of the North Anatolian Fault Zone, Earth Planets Space, 52, 293–298, 2000.

    Article  Google Scholar 

  • Ito, A., B. Üçer, S. Barış, A. Nakamura, Y. Honkura, T. Kono, S. Hori, A. Hasegawa, R. Pektaş, T. Komut, and A. M. Işıkara, Aftershock activity of 1999 Izmit earthquake, Turkey, revealed from microearthquake observations, Bull. Seismol. Soc. Am., 92, 418–427, 2002.

    Article  Google Scholar 

  • Kasaya, T., N. Oshiman, N. Sumitomo, M. Uyeshima, Y. Iio, and D. Uehara, Resistivity structure around the hypocentral are of the 1984 Western Nagano Prefecture earthquake in central Japan, Earth Planets Space, 54, 107–118, 2002.

    Article  Google Scholar 

  • Mackie, R. L., T. R. Madden, and P. E. Wannamaker, Three-dimensional magnetotelluric modeling using finite difference equations—Theory and comparisons to integral equation solutions, Geophysics, 58, 215–226, 1993.

    Article  Google Scholar 

  • Mitsuhata, Y., Y. Ogawa, M. Mishina, T. Kono, T. Yokokura, and T. Uchida, Electromagnetic heterogeneity of the seismogenic region of 1962 M6.5 Northern Miyagi Earthquake, northeastern Japan, Geophys. Res. Lett., 28, 4371–4374, 2001.

    Article  Google Scholar 

  • Nesbitt, B. E., Electrical resistivity of crustal fluids, J. Geophys. Res., 98, 4301–4310, 1993.

    Article  Google Scholar 

  • Ogawa, Y. and T. Uchida, A two-dimensional magnetotelluric inversion assuming Gaussian static shift, Geophys. J. Int., 126, 69–76, 1996.

    Article  Google Scholar 

  • Ogawa, Y., M. Mishina, T. Goto, H. Satoh, N. Oshiman, T. Kasaya, Y. Takahashi, T. Nishitani, S. Sakanaka, M. Uyeshima, Y. Takahashi, Y. Honkura, and M. Matsushima, Magnetotelluric imaging of fluids, in intraplate earthquake zones, NE Japan back arc, Geophys. Res. Lett., 28, 3741–3744, 2001.

    Article  Google Scholar 

  • Ogawa, Y., S. Takakura, and Y. Honkura, Resistivity structure across Itoigawa-Shizuoka tectonic line and its implications for concentrated deformation, Earth Planets Space, 54, 1115–1120, 2002.

    Article  Google Scholar 

  • Oshiman, N., R. Yoshimura, T. Kasaya, Y. Honkura, M. Matsushima, S. Bariş, C. Çelik, M. K. Tunçer, and A. M. Işikara, Deep resistivity structure around the fault associated with the 1999 Kocaeli earthquake, Turkey, in Seismotectonics in Convergent Plate Boundary, edited by Y. Fujinawa and A. Yoshida, pp. 293–303, Terra Sci. Publ. Company, Tokyo, 2002.

    Google Scholar 

  • Pınar, A., Y. Honkura, and K. Kuge, Seismic activity triggered by the 1999 Izmit earthquake and its implications for the assessment of future seismic risk, Geophys. J. Int., 146, F1–F7, 2001.

    Article  Google Scholar 

  • Unsworth, M. J., P. A. Bedrosian, M. Eisel, G. D. Egbert, and W. Siripunvaraporn, Along strike variations in the electrical structure of the San Andreas Fault at Parkfield, California, Geophys. Res. Lett., 27, 3021–3024, 2000.

    Article  Google Scholar 

  • Yagi, Y. and M. Kikuchi, Source rupture process of the Kocaeli, Turkey, earthquake of August 17, 1999, obtained by joint inversion of near-field data and teleseismic data, Geophys. Res. Lett., 27, 1969–1972, 2000.

    Article  Google Scholar 

  • Yılmaz, Y., S. C. Genç, E. Yigitbaş, M. Bozcu, and K. Yılmaz, Geological evolution of the late Mesozoic continental margin of Northwestern Anatolia, Tectonophysics, 243, 155–171, 1995.

    Article  Google Scholar 

  • Zhao, D., H. Kanamori, and H. Negishi, Tomography of the source area of the 1995 Kobe earthquake: evidence for fluids at the hypocenter?, Science, 274, 1891–1894, 1996.

    Article  Google Scholar 

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Tank, S.B., Honkura, Y., Ogawa, Y. et al. Resistivity structure in the western part of the fault rupture zone associated with the 1999 İzmit earthquake and its seismogenic implication. Earth Planet Sp 55, 437–442 (2003). https://doi.org/10.1186/BF03351777

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  • DOI: https://doi.org/10.1186/BF03351777

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