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Preliminary report on the Sanyi-Puli seismic zone conductivity anomaly and its correlation with velocity structure and seismicity in the Northwestern Taiwan

Abstract

As part of seismotectonic investigations in Northwestern Taiwan, eight magnetotelluric (MT) soundings were conducted across the Sanyi-Puli seismic zone, a distinct NW-SE trending linear seismic zone in the fold-thrust belt of Northwestern Taiwan. A preliminary one-dimensional resistivity model according to the determinant MT response was computed, and the resistivity model includes a high-conductivity anomaly beneath this seismic zone. This conductivity anomaly raises the possibility of metamorphic dehydration triggering the seismic events in the seismic zone. The correlation between the conductivity anomaly and active seismicity in this area is tentatively discussed in this study.

References

  • Ague, J. J., J. Park, and D. M. Rye, Regional metamorphic dehydration and seismic hazard, Geophys. Res. Lett., 25, 4221–4224, 1998.

    Article  Google Scholar 

  • Bailey, R. C., Trapping of aqueous fluids in the deep crust, Geophys. Res. Lett., 17, 1129–1132, 1990.

    Article  Google Scholar 

  • Chen, C. H. and C. H. Wang, Explanatory notes for the metamorphic facies map of Taiwan, Second Edition, 51 pp., Central Geological Survey, MOEA, Taipei, Taiwan, 1995 (in Chinese).

    Google Scholar 

  • Deffontaines, B., J. C. Lee, J. Angelier, J. Carvalho, and J. P. Rudant, New geomorphic data on the active Taiwan orogen: A multisource approach, J. Geophys. Res., 99, 20,243–20,266, 1994.

    Article  Google Scholar 

  • Groom, R. W. and R. C. Bailey, Decomposition of magnetotelluric impedance tensor in the presence of local three-dimensional galvanic distortion, J. Geophys. Res., 94, 1913–1925, 1989.

    Article  Google Scholar 

  • Gudmundsson, A., Fluid overpressure and stress drop in fault zones, Geophys. Res. Lett., 26, 115–118, 1999.

    Article  Google Scholar 

  • Hsu, C. H., C. I. Lee, and J. F. Lee, NW-SE trending seismic zone in the Miaoli-Taichung-Nantou area, Central Taiwan, and its implication in tectonics, in Proceedings of The Sixth Symposium on Taiwan Quaternary, pp. 224–228, 1996 (in Chinese).

  • Ingham, M. R., The use of invariant impedances in magnetotelluric interpretation, Geophys. J. Int., 92, 165–169, 1988.

    Article  Google Scholar 

  • Jones, A. G., Electrical conductivity of the continental lower crust, in Continental Lower Crust, edited by D. M. Fountain, R. J. Arculus, and R. W. Kay, pp. 81–143, Elsevier, New York, 1992.

    Google Scholar 

  • Lee, S. J., The S-wave velocity structure under central-western Taiwan by strong ground motion waveform modeling, M Sc. thesis, Nat. Central Univ., 138 pp., Chungli, Taiwan, 1999 (in Chinese).

    Google Scholar 

  • Lin, C. H. and S. W. Roecker, Deep earthquakes beneath central Taiwan: mantle shearing in an arc-continent collision, Tectonics, 12, 745–755, 1993.

    Article  Google Scholar 

  • Oldenburg, D. W. and R. G. Ellis, Efficient inversion of magnetotelluric data in two dimensions, Phys. Earth Planet. Inter., 81, 177–200, 1993.

    Article  Google Scholar 

  • Pellerin, L. and G. W. Hohmann, Transient electromagnetic inversion: A remedy for magnetotelluric static shifts, Geophysics, 55, 1242–1250, 1990.

    Article  Google Scholar 

  • Ranganayaki, R. P., The interpretive analysis of magnetotelluric data, Geophysics, 49, 1730–1748, 1984.

    Article  Google Scholar 

  • Rau, R. J., J. C. Lee, H. Kao, and H. T. Chu, Transition from convergence to escape: inferences from seismic tomography, seismicity, and focal mechanisms in the foreland belt of central-western Taiwan, J. Geophys. Res., 1998 (submitted).

  • Seno, T., S. Stein, and A. E. Gripp, A model for the motion of the Philippine Sea plate consistent with NUVEL-1 and geological data, J. Geophys. Res., 98, 17,941–17,948, 1993.

    Article  Google Scholar 

  • Suppe, J., Mechanics of mountain building and metamorphism in Taiwan, Mem. Geol. Soc. China, 4, 67–89, 1981.

    Google Scholar 

  • Suppe, J. and J. H. Wittke, Abnormal pore-fluid pressures in relation to stratigraphy and structure in the active fold-and-thrust belt of northwestern Taiwan, Petrol. Geol. Taiwan, 14, 11–24, 1977.

    Google Scholar 

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Correspondence to Chien-chih Chen.

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Chen, Cc., Chen, Cs. Preliminary report on the Sanyi-Puli seismic zone conductivity anomaly and its correlation with velocity structure and seismicity in the Northwestern Taiwan. Earth Planet Sp 52, 377–381 (2000). https://doi.org/10.1186/BF03351649

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  • DOI: https://doi.org/10.1186/BF03351649

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