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The observation of ULF emissions at Nakatsugawa in possible association with the 2004 Mid Niigata Prefecture earthquake

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The observation of ULF/ELF electromagnetic emissions at Nakatsugawa, Gifu, has indicated that ULF emissions in the frequency below 0.1 Hz take place about two-three weeks before the 2004 Mid Niigata Prefecture earthquakes. The most important support to this is based on the goniometric direction finding for those ULF emissions in the period of October 2–6, which indicates their azimuth being very close to the epicenters of the earthquake. So, these ULF emissions on October 2–6 are likely to be associated with the 2004 Mid Niigata Prefecture earthquake.


  1. Hayakawa, M., Whistlers, Chapt. 7 in Handbook of Atmospheric Electrodynamics, edited by H. Volland, CRC Press, Boca Raton, 1995.

  2. Hayakawa, M. (ed.), Atmospheric and Ionospheric Electromagnetic Phenomena Associated with Earthquakes, Terra Sci. Pub. Co., Tokyo, 996 pp., 1999.

  3. Hayakawa, M. and K. Hattori, Ultra-low-frequency electromagnetic emissions associated with earthquakes, Special Issue on Recent Progress in Electromagnetic Theory and its Application, Inst. Electr. Engrs. Japan, Trans. Fundamentals and Materials, 124, 1101–1108, 2004.

  4. Hayakawa, M. and O. A. Molchanov (ed.), Seismo Electromagnetics: Lithosphere—Atmosphere—Ionosphere Coupling, TERRAPUB, Tokyo, 477 pp., 2002.

  5. Kawate, R., O. A. Molchanov, and M. Hayakawa, Ultra-low-frequency magnetic fields during the Guam earthquake of 8 August 1993 and their interpretation, Phys. Earth Planet. Inter., 105, 239–248, 1998.

  6. Molchanov, O. A. and M. Hayakawa, Generation of ULF electromagnetic emissions by microfracturing, Geophys. Res. Lett., 22, 3091–3094, 1995.

  7. Nickolaenko, A. P. and M. Hayakawa, Resonances the Earth-Ionosphere Cavity, Kluwer Acad. Pub., Dordrecht, 2002.

  8. Ohta, K., K. Umeda, N. Watanabe, and M. Hayakawa, ULF/ELF emissions observed in Japan, possibly associated with the Chi-Chi earthquake in Taiwan, Natural Hazards Earth System Sci., 1, 37–42, 2001.

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Correspondence to Masashi Hayakawa.

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Ohta, K., Watanabe, N. & Hayakawa, M. The observation of ULF emissions at Nakatsugawa in possible association with the 2004 Mid Niigata Prefecture earthquake. Earth Planet Sp 57, 1103–1108 (2005) doi:10.1186/BF03351889

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Key words

  • Seismogenic ULF emissions
  • 2004 Mid Niigata Prefecture earthquake
  • goniometric direction finding