Skip to main content


We’d like to understand how you use our websites in order to improve them. Register your interest.

Recent progress of seismic observation networks in Japan —Hi-net, F-net, K-NET and KiK-net—


After the disastrous 1995 Kobe earthquake, a new national project has started to drastically improve seismic observation system in Japan. A large number of strong-motion, high-sensitivity, and broadband seismographs were installed to construct dense and uniform networks covering the whole of Japan. The new high-sensitivity seismo-graph network consisting of 696 stations is called Hi-net, while the broadband seismograph network consisting of 71 stations is called F-net. At most of Hi-net stations strong-motion seismographs are also equipped both at depth and the ground surface. The network of these 659 stations with an uphole/downhole pair of strong-motion seismographs is called KiK-net, while another network consisting of 1034 strong-motion seismographs installed at the ground surface is called K-NET. Here, all the station numbers are as of April 2003. High-sensitivity data from Hi-net and pre-existing seismic networks operated by various institutions have been transmitted to and processed by the Japan Meteorological Agency since October 1997 to monitor the seismic activity in and around Japan. The same data are shared to university group in real time using satellite communication for their research work. The data are also archived at the National Research Institute for Earth Science and Disaster Prevention and stored in their database system for public use under a fully open policy.


  1. Aoi, S., K. Obara, S. Hori, K. Kasahara, and Y. Okada, New Japanese uphole/downhole strong-motion observation network: KiK-net, Seism. Res. Lett., 72, 239, 2000.

  2. Fukushima, Y. and T. Tanaka, A new attenuation relation for peak horizontal acceleration of strong earthquake ground motion in Japan, Bull. Seism. Soc. Am., 80, 757–783, 1990.

  3. Fukuyama, E., M. Ishida, S. Hori, S. Sekiguchi, and S. Watada, Broadband seismic observation conducted under the FREESIA project, Rep. Natl. Res. Inst. Earth Sci. Disas. Prev., 57, 23–31, 1996 (in Japanese with English abstract).

  4. Fukuyama, E., M. Ishida, D. S. Dreger, and H. Kawai, Automated seismic moment tensor determination by using on-line broadband seismic waveforms, Zisin (J. Seism. Soc. Japan), 51, 149–156, 1998 (in Japanese with English abstract).

  5. Fukuyama, E., A. Kubo, H. Kawai, and K. Nomura, Seismic remote monitoring of stress field, Earth Planets Space, 53, 1021–1026, 2001

  6. Hamada, K., M. Ohtake, Y. Okada, S. Matsumura, and H. Sato, A high quality digital network for microearthquake and ground tilt observations in the Kanto-Tokai area, Japan, Earthq. Pred. Res., 3, 447–469, 1985.

  7. Hatanaka, Y., T. Iizuka, M. Sawada, A. Yamagiwa, Y. Kikuta, J. M. Johnson, and C. Rocken, Improvement of the analysis strategy of GEONET, Bull. Geograph. Surv. Inst., 49, 11–37, 2003.

  8. Honda, R., S. Aoi, N. Morikawa, H. Sekiguchi, T. Kunugi, and H. Fujiwara, Ground motion and rupture process of the 2003 Tokachi-oki earthquake obtained from strong motion data of K-NET and KiK-net, Earth Planets Space, 56, 317–322, 2004.

  9. Kamae, K. and H. Kawabe, Source model composed of asperities for the 2003 Tokachi-oki, Japan, earthquake (MJMA=8.0) estimated by the empirical Green’s function method, Earth Planets Space, 56, 323–327, 2004.

  10. Kinoshita, S., Kyoshin-net (K-NET), Seism. Res. Lett., 69, 309–332, 1998.

  11. Koketsu, K., K. Hikima, S., Miyazaki, and S. Ide, Joint inversion of strong motion and geodetic data for the source process of the 2003 Tokachi-oki, Hokkaido, earthquake, Earth Planets Space, 56, 329–334, 2004.

  12. Kubo, A., E. Fukuyama, H. Kawai, and K. Nomura, NIED seismic moment tensor catalogue for regional earthquakes around Japan: quality test and application, Tectonophysics, 356, 23–48, 2002.

  13. Kumagai, H., T. Ohminato, M. Nakano, M. Ooi, A. Kubo, H. Inoue, and J. Oikawa, Very-long-period seismic signals and caldera formation at Miyake Island, Japan, Science, 293, 687–690, 2001.

  14. Kunugi, T., H. Fujiwara, S. Adachi, S. Aoi, and K. Kasahara, The new strong-motion seismograph of the K-NET, Abstracts 2004 Japan Earth Planet. Sci. Joint Meeting, S046–020, 2004.

  15. Matsumura, S., Y. Okada, and S. Hori, Procedures for seismic data processing by the Analyzing system for Precursors of Earthquake (APE), Rep. Natl. Res. Cent. Disas. Prev., 41, 45–64 (in Japanese with English abstract), 1988.

  16. Morita, Y. and H. Hamaguchi, Automatic detection of onset time of seismic waves and its confidence interval using the autoregressive model fitting, Zisin (J. Seism. Soc. Japan), 37, 281–293 (in Japanese with English abstract), 1984.

  17. Obara, K., Non-volcanic deep tremor associated with subduction in southwest Japan, Science, 296, 1679–1681, 2002.

  18. Obara, K., K. Kasahara, S. Hori, and Y. Okada, A densely distributed high-sensitivity seismograph network; NIED Hi-net, Japan, Rev. Scientific Instruments, 2004 (submitted).

  19. Okada, Y, Improvement of routine programs for hypocenter determination and mechanism calculation, Rep. Natl. Res. Cent. Disas. Prev., 41, 153–162, 1988 (in Japanese with English abstract).

  20. Sagiya, T., A decade of GEONET: 1994-2003—The continuous GPS observation in Japan and its impact on earthquake studies, Earth Planets Space, 56, this issue, xxix–xli, 2004.

  21. Shiomi, K., K. Obara, S. Aoi, and K. Kasahara, Estimation on the azimuth of the Hi-net and KiK-net borehole seismometers, Zisin (J. Seism. Soc. Japan), 56, 99–110, 2003 (in Japanese).

  22. Shiomi, K., H. Sato, K. Obara, and M. Ohtake, Configuration of subducting Philippine Sea plate beneath southwest Japan revealed from receiver function analysis based on the multivariate autoregressive model, J. Geo-phys. Res., 109, B04308, doi:10.1029/2003JB002774, 2004.

  23. Suzuki, H., Geology of the Koto deep borehole observatory and geological structure beneath the Metropolitan area, Japan, Rep. Natl. Res. Inst. Earth Sci. Disas. Prev., 56, 77–123, 1996 (in Japanese with English abstract).

  24. Takahashi, H., The deep borehole observatories and their contribution for revealing the characteristics of microearthquake activity in the Kanto district, Rep. Natl. Res. Cent. Disas. Prev., 28, 1–104, 1982 (in Japanese with English abstract).

  25. Urabe, T. and S. Tsukuda, WIN—A program on workstation for support of manual phase picking process on seismograms recorded by microearthquake observation network, Programme and Abstract, Seism. Soc. Japan, No. 2, P. 41, 1992 (in Japanese).

  26. Wielandt, E. and G. Streckeisen, The leaf-spring seismometer: Design and performance, Bull. Seism. Soc. Am., 72, 2349–2367, 1982.

  27. Yagi, Y., Source rupture process of the 2003 Tokachi-oki earthquake determined by joint inversion of teleseismic body wave and strong ground motion data, Earth Planets Space, 56, 311–316, 2004.

  28. Yamanaka, H., K. Motoki, K. Etoh, M. Murayama, and N. Komaba, Observation of aftershocks of the 2003 Tokachi-oki earthquake for estimation of local site effects, Earth Planets Space, 56, 335–340, 2004.

Download references

Author information



Corresponding author

Correspondence to Yoshimitsu Okada.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Okada, Y., Kasahara, K., Hori, S. et al. Recent progress of seismic observation networks in Japan —Hi-net, F-net, K-NET and KiK-net—. Earth Planet Sp 56, xv–xxviii (2004).

Download citation

Key words

  • Seismic network
  • Hi-net
  • F-net
  • K-NET
  • KiK-net