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Silent earthquakes occurring in a stable-unstable transition zone and implications for earthquake prediction

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In the past decade, nine silent earthquakes were documented along the Nankai and the Sagami Troughs in Japan, which form the northwestern margin of the Philippine Sea plate. They occurred in the stable-unstable transition zone at depths of around 30 km on the subduction interface and were segregated from major asperities of the 1923 Kanto, the 1944 Tonankai and the 1946 Nankai earthquakes. Their equivalent magnitudes were less than 7 and overall slips were less than 0.2 m, one-order smaller than those of the major asperities of ordinary great earthquakes. Moment release rates of the silent earthquakes were less than 1014 Nm/s, five-orders smaller than 1019 Nm/s of the great earthquakes. Two methodologies are attempted to obtain order of magnitude estimates of the roughness and friction parameter of source areas of some of the silent earthquakes. One method compares observed waveforms to synthetics with an empirical source time function based on laboratory experiment. The other relates sizes of silent earthquakes to the friction parameter a-b.


  1. Beroza, G. C. and T. H. Jordan, Searching for slow and silent earthquakes using free oscillations, J. Geophys. Res., 95, 2485–2510, 1990.

  2. Das, S. and C. Sholz, Theory of time-dependent rupture of the Earth, J. Geophys. Res., 86, 6039–6051, 1981.

  3. Dieterich, J. H., Modelling of rock friction: 1. Experimental result and constitutive equations, J. Geophys. Res., 84, 2161–2168, 1979.

  4. Dieterich, J. H., A model for the nucleation of earthquake slip, in Earthquake source mechanisms, M. EWING Ser. 6, edited by S. Das, J. Boatright, and C. H. Scholz, pp. 579–592, AGU, Washington, D.C., 1986.

  5. Dieterich, J. H., Earthquake nucleation on faults with rate-dependent and state-dependent strength, Tectonophysics, 211, 115–134, 1992.

  6. Dieterich, J. H., A constitutive law for rate of earthquake production and its application to earthquake clustering, J. Geophys. Res., 99, 2601–2618, 1994.

  7. Dragert, H., K. Wang, and T. S. James, A silent slip event on the deeper Cascadia subduction interface, Science, 292, 1525–1528, 2001.

  8. Ellsworth, W. L. and G. C. Beroza, Observation of the seismic nucleation phase in the 1995 Ridgecrest, California sequence, Geophys. Res. Inst., 25, 401–404, 1998.

  9. Freymueller, J. T., S. Hreinsdottir, C. Zweck, and P. J. Haeussler, The 1998–2002 deep megathrust slip event, Alaska, AGU 2002 Fall Meeting, G61A-0972, 2002.

  10. Fujii, Y., Vertical crustal movement in the Boso peninsula, South Kanto, Japan, as deduced from the adjustment of a geodetic network with signals, Tectonophysics, 218, 309–322, 1993.

  11. GSI, Crustal movements in the Kanto district, Report of the Coordinating Committee for Earthquake Prediction, 69, 138–175, 2003a (in Japanese).

  12. GSI, Crustal movements in the Tokai district, Report of the Coordinating Committee for Earthquake Prediction, 70, 204–299, 2003b (in Japanese).

  13. GSI, Crustal movements in the Chugoku, Shikoku and Kyushu districts, Report of the Coordinating Committee for Earthquake Prediction, 71, 680–694, 2004 (in Japanese).

  14. Harada, S., Y. Nakagawa, I. Kawasaki, and T. Sagiya, A preliminary report on February, 1999, silent earthquake off Boso peninsula, central Japan, as revealed by GEONET, Abstracts 2000 Japan Earth and Planetary Science Joint Meeting, Da009, 2000 (in Japanese).

  15. Hatanaka, Y., T. IIzuka, M. Sawada, A. Yamagiwa, Y. Kikuta, J. M. Johnson, and C. Roken, Improvement of the analysis strategy of GEONET, Bulletin of Geographical Survey Institute, 49, 11–37, 2003.

  16. Hirose, H., K. Hirahara, F. Kimata, N. Fujii, and S. Miyazaki, A slow thrust slip event following the two 1996 Hyuganada earthquakes beneath the Bungo Channel, southwest Japan, Geophys. Res. Lett., 26, 3237–3240, 1999.

  17. Hirose, H., K. Hirahara, and N. Fujii, Possible slow slip recurrence off Boso peninsula, Programme and Abstracts The seismological society of Japan 2001 Fall meeting, P140, 2001 (in Japanese).

  18. Hirose, I., I. Kawasaki, Y. Okada, T. Sagiya, and Y. Tamura, A silent earthquake of December 9, 1989, in the Tokyo bay, as revealed by the continuous observation of crustal movements in the southern Kanto district, central Japan, Zisin, 53, 11–23, 2000 (in Japanese).

  19. Hyndman, R. D. and K. Wang, Thermal constraints on the zone of major thrust earthquake failure: The Cascade subduction zone, J. Geophys. Res., 98, 2039–2060, 1993.

  20. Ishida, M., Geometry and relative motion of the Philippine Sea plate and Pacific plate beneath the Kanto-Tokai district, Japan, J. Geophys. Res., 97, 489–515, 1992.

  21. Ito, T., Y. Yoshioka, and S. Miyazaki, Interplate coupling in southwest Japan deduced from inversion analysis of GPS data, Phys. Earth Planet. Interiors, 115, 17–34, 1999.

  22. Kanamori, H., Tectonic implication of the 1944 Tonankai and the 1946 Nankaido earthquakes, Phys. Earth Planet. Interiors, 5, 129–139, 1972.

  23. Kanamori, H. and M. Kikuchi, The 1992 Nicaragua earthquake: A slow tsunami earthquake associated with subducted sediments, Nature, 361, 714–716, 1993.

  24. Kanda, K., M. Takemura, and T. Usami, Inversion analysis of distribution of energy radiated from an earthquake fault based on the seismic intensity data, Zisin, 56, 39–58, 2003 (in Japanese).

  25. Kato, N. and T. Hirasawa, Nonuniform and unsteady sliding of a plate boundary in a great earthquake cycle: A numerical simulation using a laboratory-derived friction law, Pure Appl. Geophys., 155, 93–118, 1999.

  26. Kato, N., Repeating slip events at s circular asperity: Numerical simulation with a rate- and state-dependent friction law, Bull. Earthq. Res. Inst., 78, 151–166, 2003.

  27. Kawamura, M., K. Yamaoka, H. Hirose, and K. Hirahara, Time-to-failure analysis for the anomaly of the crustal movement in the Tokai region, Abstracts 2000 Japan Earth and Planetary Science Joint Meeting, S046-P003, 2002 (in Japanese).

  28. Kawasaki, I., Y. Asai, Y. Tamura, T. Sagiya, N. Mikami, Y. Okada, M. Sakata, and M. Kasahara, The 1992 Sanriku-Oki, Japan, ultra-slow earthquake, J. Phys. Earth, 43, 105–116, 1995.

  29. Kawasaki, I., Y. Asai, and Y. Tamura, Space-time distribution of interplate moment release including slow earthquakes and the seismo-geodetic coupling in the Sanriku-oki region along the Japan trench, Tectonophysics, 300, 267–283, 2001.

  30. Kikuchi, M., M. Nakamura, and K. Yoshikawa, Source rupture process of the 1944 Tonankai earthquake and the 1945 Mikawa earthquake derived from low-gain seismograms, Earth Planets Space, 55, 159–172, 2003.

  31. Kimata, F., K. Hirahara, and N. Fujii, Interplate coupling changes in the Tokai region, Japan, estimated from the vertical movements by leveling and tide gauge during 1960-2002, AGU 2002 Fall Meeting, G61A-0978, 2002.

  32. Kuwahara, Y., M. Ohnaka, K. Yamamoto, and T. Hirasawa, Earthquake faulting and fault surface topography, Report of collaborative research project on Fractal and Fracture phenomena, Mathematical seismology II, The Institute of Statistical Mathematics, 36–48, 1987 (in Japanese).

  33. Lowry, A. R., K. M. Larson, V. Kostoglodov, and R Bilham, Transient fault slip in Guerrero, southern Mexico, Geophys. Res. Lett., 28, 3753–3756, 2001.

  34. Linde, A. T., K. Suyehiro, S. Miura, I. S. Sacks, and A. Takagi, Episodic aseismic slip, stress distribution and seismicity, Nature, 334, 513–515, 1988.

  35. Main, I. G., Applicability of time-to-failure analysis to accelerated strain before earthquakes and volcanic eruptions, Geophys. J. Int., 139, F1–F6, 1999.

  36. Miyoshi, T. and K. Ishibashi, Geometry of the upper surface of the Philippine sea slab, in Proc. of Physics of arc and back arc associated with the subduction of the Philippine sea plate, edited by I. Nakanishi, Disaster Prevention Institute, Kyoto University, pp. 127–137, 2002 (in Japanese).

  37. Nakamura, M., H. Watanabe, T. Konomi, S. Kimura, and M. Miura, Characteristic activities of subcrustal earthquakes along the outer zone of southwest Japan, Annuals of the Disaster Prevention Research Institute, 40, B, 1–20, 1997 (in Japanese).

  38. Obara, K., Nonvolcanic deep tremor associated with subduction in southwest Japan, Science, 296, 1679–1681, 2002.

  39. Ohnaka, M. and L.-F. Shen, Scaling of the rupture process from nucleation to dynamic propagation: Implications of geometric irregularity of the rupturing surfaces, J. Geophys. Res., 104(B1), 817–844, 1999.

  40. Ohnaka, M., A physical scaling relation between the size of an earthquake and its nucleation zone size, Pure and Applied Geophysics, 157, 2259–2282, 2000.

  41. Ozawa, S., M. Murakami, and T. Tada, Time-dependent inversion study of the slow thrust event in the Nankai trough subduction zone, southwest Japan, J. Geophys. Res., 787–802, 2001.

  42. Pelayo, A. M. and D. W. Wiens, Tsunami earthquake: Slow thrust-faulting events in the accretionary wedge, J. Geophys. Res., 97(B11), 15321–15337, 1992.

  43. Sagiya, T. and W. Thatcher, Coseismic slip resolution along a plate boundary megathrust: The Nankai Trough, southwest Japan, J. Geophys. Res., 104, 1111–1129, 1999.

  44. Sagiya, T., Interplate coupling in the Tokai district, central Japan, deduced from continuous GPS data, Geophys. Res. Lett., 26, 2315–2318, 1999.

  45. Sagiya, T., Interplate coupling in the Kanto District, central Japan, and the Boso Silent earthquake in May 1996, PAGEOPH, 2004 (in press).

  46. Sato, R., Theoretical basis on relationships between focal parameters and earthquake magnitude, J. Phys. Earth, 27, 353–372, 1979.

  47. Seno, T., S. Stein, and A. 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.

  48. Shibazaki, B. and M. Matsu’ura, Transition process from nucleation to high speed rupture propagation: Scaling from stick-slip experiments to natural ai]earthquakes, Geophys. J. Int., 132, 14–30, 1998.

  49. Tanioka, Y. and K. Satake, Coseismic slip distribution of the 1946 Nankai earthquake and aseismic slips caused by the earthquake, Earth Planets Space, 53, 4, 235–241, 2001.

  50. Varnes, D. J., Predicting earthquakes by analyzing accelerating precursory seismic activity, Pure Appl. Geophys., 130, 661–686, 1989.

  51. Wald, D. J. and P. G. Somerville, Variable-slip rupture model of the great 1923 Kanto, Japan, Earthquake: Geodetic and body-waveform analysis, Bull. Seism. Soc. Am., 85, 159–177, 1995.

  52. Yagi, Y., M. Kikuchi, and T. Sagiya, Co-seismic slip, post-seismic slip, and aftershocks associated with two large earthquakes in 1996 in Hyuga-nada, Japan, Earth Planets Space, 53, 793–803, 2001.

  53. Yoshida, S. and N. Kato, Episodic aseismic slip in a two-degree-of-freedom block-spring model, Geophys. Res. Lett., 30, 13, 1681–1684, 2003.

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Correspondence to Ichiro Kawasaki.

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Kawasaki, I. Silent earthquakes occurring in a stable-unstable transition zone and implications for earthquake prediction. Earth Planet Sp 56, 813–821 (2004) doi:10.1186/BF03353088

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Key words

  • Silent earthquake
  • fault roughness
  • stable-unstable transition zone
  • Nankai Trough
  • Sagami Trough