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An improved double-difference earthquake location algorithm using s P phases: application to the foreshock and aftershock sequences of the 2004 earthquake offshore of the Kii peninsula, Japan (Mw=7.5)
Earth, Planets and Space volume 58, pages 823–830 (2006)
Abstract
We have used s P phases to improve the hypocentral locations of the earthquakes that occurred offshore southeast of the Kii peninsula in association with the Mw=7.5 mainshock on September 5, 2004. The earthquakes were more than 100 km from the onshore seismic network and, thus, their focal depths were poorly constrained. The s P phases were recorded about 7–11 s after the initial P phases, with both phases having almost the same apparent velocities. The computation of ray-paths revealed that the arrival times of the later s P phases are sensitive to focal depths. We have recalculated the hypocenters and origin times for 36 events with more than six s P phase identifications on seismograms recorded at the High Sensitivity Seismograph Network by including s P phases in a double-difference earthquake location algorithm, which eliminates the errors introduced by crustal heterogeneity. The relocation results were then compared with those from the Japan Meteorological Agency based on traditional absolute location techniques.
References
Ando, M., Source mechanism and tectonic significance of historical earthquake along the Nankai Trough, Japan, Tectonics, 27, 119–140, 1975.
Bai, L., T. Z. Zhang, and H. Z. Zhang, Multiplet relative location approach and waveform correlation correction and their application, Acta Seismol. Sinica, 16, 606–615, 2003.
Bai, L., Z. L. Wu, T. Z. Zhang, and I. Kawasaki, The effect of distribution of stations upon location error accuracy: statistical tests based on the double-difference earthquake location algorithm and the bootstrap method, Earth Planets Space, 58, e9–e12, 2006.
Cêrvenyý, V., I. Molotkov, and I. Pšencîk, Ray method in seismology, University of Karlova, Prague, Czechoslovakia, 1977.
Enescu, B., J. Mori, and S. Ohmi, Double-difference relocations of the 2004 off the Kii peninsula earthquakes, Earth Planets Space, 57, 357–362, 2005.
Engdahl, E. R. and S. Billington, Focal depth determination of central Aleutian earthquakes, Bull. Seismol. Soc. Am., 76, 77–93, 1986.
Engdahl, E. R., R. Hilst, and R. Buland, Global teleseismic earthquake relocation with improved travel times and procedures for depth determination, Bull. Seismol. Soc. Am., 88, 722–743, 1998.
Gamage, S. S., Offshore double-planed shallow seismicity in the northeastern Japan forearc region revealed by sP depth phase, Master thesis, Tohoku Univ., 96 pp, 2005.
Ishikawa, Y., The shape of the Philippine Sea slab, Journal of Geography, 110, 592–601, 2001 (in Japanese with English abstract).
Lay, T., D. H. Christensen, L. Astiz, and H. Kanamori, Temporal variation of large intraplate earthquakes in coupled subduction zones, Phys. Earth Planet. Inter, 54, 258–312, 1989.
Menke, W. and D. Schaff, Absolute earthquake locations with differential data, Bull. Seismol. Soc. Am., 94, 2254–2264, 2004.
Miyoshi, T. and K. Ishibashi, A tectonic interepretation of NW-SE strike-slip faulting during the 2004 off the Kii peninsula earthquakes, Japan: Probable tear of the Philippine Sea plate, Earth Planets Space, 57, 1115–1120, 2005.
Nakamura, M., H. Watanabe, T. Konomi, S. Kimuta, and K. Miura, Characteristic activities of subcrustal earthquakes along the outer zone of southwestern Japan, Annu. Disaster Prevention Res. Inst., 40B-1, 1997 (in Japanese with English abstract).
Nakanishi, A., N. Takahashi, J.-O. Park, S. Miura, S. Kodaira, Y. Kaneda, N. Hirata, T. Iwasaki, and M. Nakamura, Crustal structure across the coseismic rupture zone of the 1944 Tonankai earthquake, the central Nankai Trough seismogenic zone, J. Geophys. Res., 107, doi: 10. 1029/2001JB000424, 2002.
Obana, K., S. Kodaira, Y. Kaneda, K. Mochizuki, and M. Shinohara, Microseismicity at the seaward updip limit of the western Nankai Trough seismogenic zone, J. Geophys. Res., 108, doi: 10.1029/2002JB002370, 2003.
Park, S.-C. and J. Mori, The 2004 sequence of triggered earthquakes off the Kii Peninsula, Japan, Earth Planets Space, 57, 315–320, 2005.
Pavlis, G. L., Appraising earthquake hypocenter location errors: a complete practice approach for single-event locations, Bull. Seismol. Soc. Am., 76, 1699–1717, 1986.
Pearce, R. G., Complex P waveforms from a Gulf of Aden earthquake, Geophys. J., 64, 187–200, 1981.
Sakai, S., T. Yamada, M. Shinohara, H. Hagiwara, T. Kanazawa, K. Obana, S. Kodaira, and Y. Kaneda, Urgent aftershock observation of the 2004 off the Kii peninsula earthquake using ocean bottom seismometers, Earth Planets Space, 57, 363–368, 2005.
Satake, K., T. Baba, K. Hirata, S. Iwasaki, T. Kato, S. Koshimura, J. Takenaka, and Y. Terada, Tsunami source of the 2004 off the Kii Peninsula earthquakes inferred from offshore tsunami and coastal tide gauges, Earth Planets Space, 57, 173–178, 2005.
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, 17941–17948, 1993.
Seno, T., The September 5, 2004 off the Kii Peninsula earthquakes as a composition of bending and collision, Earth Planets Space, 57, 327–332, 2005.
Umino, N., A. Hasegawa, and T. Matsuzawa, s P depth phase at small epicentral distances and estimated subduction plate boundary, Geophys. J. Int., 120, 356–366, 1995.
Waldhauser, F. and W. L. Ellsworth, A double-difference earthquake location algorithm: method and application to the Northern Hayward Fault, California, Bull. Seismol. Soc. Am., 90, 1353–1368, 2000.
Wang, Z. and D. P. Zhao, Seismic imaging of the entire arc of Tohoku and. Hokkaido in Japan using P-wave, S-wave and sP depth-path data, Phys. Earth Planet. Inter., 152, 144–162, 2005.
Yagi, Y., http://iisee.kenken.go.jp/staff/yagi/eq/Japan20040905/Japan20040905_1-j.html, 2005 (in Japanese). ai]Yoshioka, S. and Y. Ito, Lateral variations of effective elastic thickness of the subducting Philippine Sea plate along the Nankai trough, Earth Planets Space, 53, 261–273, 2001.
Zelt, C. A. and R. B. Smith, Seismic traveltime inversion for 2-D crustal. velocity structure, Geophys. J. Int., 108, 16–34, 1992.
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Bai, L., Kawasaki, I., Zhang, T. et al. An improved double-difference earthquake location algorithm using s P phases: application to the foreshock and aftershock sequences of the 2004 earthquake offshore of the Kii peninsula, Japan (Mw=7.5). Earth Planet Sp 58, 823–830 (2006). https://doi.org/10.1186/BF03351987
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DOI: https://doi.org/10.1186/BF03351987