JDR Vol.12 No.6 pp. 1109-1116
doi: 10.20965/jdr.2017.p1109

Survey Report:

New Japanese Guidelines for the Information of the Prospect of Seismic Activity After Large Earthquakes and Their Applications

Noriko Kamaya*,†, Kiyoshi Takeda*, and Tetsuo Hashimoto**

*Seismology and Volcanology Department, Japan Meteorological Agency
1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan

Corresponding author

**Seismology and Tsunami Research Department, Meteorological Research Institute, Ibaraki, Japan

August 1, 2017
November 25, 2017
Online released:
November 29, 2017
December 1, 2017
Kumamoto Earthquake, prospect of seismic activity, aftershock probability, seismic information, aftershock

The Kumamoto Prefecture suffered an earthquake of MJMA6.5 on April 14, 2016 at 21:26 (Japan Standard Time). A seismic intensity of 7, on the Japan Meteorological Agency (JMA) seismic intensity scale, was observed, which, by definition, is the maximum possible value. After 18 hours of the earthquake, the JMA issued a prospect for aftershock activity, where the probability of aftershocks with a seismic intensity of 6 Lower (6-) or greater, was 20% within three days following 16:00 JST on April 15, 2016. Ten hours post the issuance of the prospect, at 01:25 on April 16, a larger earthquake of MJMA7.3, with a maximum JMA seismic intensity of 7, occurred in the same region as the MJMA6.5 event, triggering many distant earthquakes. As this seismic occurrence did not follow a mainshock-aftershock sequence, the JMA discontinued the issuance of prospective aftershock activity. With lessons learned from this occurrence sequence, the Earthquake Research Committee of Japan (ERC), including JMA, seismologists and social scientists, have formulated new guidelines for the assessment of successive seismic activity, in order to enhance the understanding of strong ground motions after large earthquakes. The five main points of the guidelines are as follows: (1) alert to a similar strong ground motion, (2) highlighting previous examples of successive large events, (3) consideration of all active source faults, (4) quantitative forecasting of aftershocks a week after the event, and (5) not using the term “aftershock” in information issued by the JMA for disaster prevention. The JMA has commenced the implementation of these new guidelines, effective August 2016.

  1. [1] [accessed July 23, 2017]
  2. [2] T. Utsu, “A statistical study on the occurrence of aftershocks,” Geophys. Mag., 30, pp. 521-605, 1961.
  3. [3] B. Gutenberg and C. F. Richter, “Seismicity of the Earth,” Geological Society of America, Vol.34, p. 131, 1941.
  4. [4] [accessed July 23, 2017]
  5. [5] Japan Meteorological Agency and Meteorological Research Institute, “The 2016 Kumamoto Earthquake,” Report of the Coordinating Committee for Earthquake Prediction, Vol.96, pp. 492-556, 2016.
  6. [6],p.26 [accessed July 18, 2017]
  7. [7] [accessed July 20, 2017]
  8. [8] [accessed July 21, 2017]
  9. [9] [accessed July 20, 2017]
  10. [10] [accessed July 21, 2017]
  11. [11] [accessed July 21, 2017]
  12. [12] M. Miyazawa, “An investigation into the remote triggering of the Oita earthquake by the 2016 Mw 7.0 Kumamoto earthquake using full wavefield simulation,” Earth, Planets and Space, Vol.68:205, DOI:10.1186/s40623-016-0585-z, 2016.
  13. [13] [accessed July 21, 2017]
  14. [14] [accessed July 21, 2017]
  15. [15] Y. Ogata, “Statistical models for earthquake occurrences and residual analysis for point processes,” Mathematical Seismology, Vol.1, pp. 228-281, Inst. Statist. Math., 1986.
  16. [16] Y. Ogata, “Statistical models for earthquake occurrences and residual analysis for point processes,” J. Am. Stat. Assoc., Vol.83, pp. 9-27, 1988.
  17. [17] Y. Ogata, “Statistical model for standard seismicity and detection of anomalies by residual analysis,” Tectonophysics, Vol.169, pp. 159-174, 1989.
  18. [18] Y. Ogata, “Detection of precursory relative quiescence before great 23 earthquakes through a statistical model,” J. Geophys. Res., Vol.97, pp. 19845-19871, 1992.
  19. [19] Y. Ogata, “Seismological application of statistical methods for point-process modeling,” Proc. of the first US/Japan conf. on Frontiers of Statistical Modeling, ed. H. Bozdogan, pp. 37-163, Kluwer, Academic Publishers, Dordrecht, 1994.
  20. [20] Y. Ogata and K. Shimazaki, “Transition from aftershock to normal activity,” Bull. Seismol. Soc. Am., Vo.74, pp. 1757-1765, 1984.
  21. [21] Y. Ogata and H. Tsuruoka, “Statistical monitoring of aftershock sequences: a case study of the 2015 Mw7.8 Gorkha, Nepal, earthquake,” Earth, Planets and Space, 68:44, doi:10.1186/s40623-016-0410-8, 2016.
  22. [22] H. Akaike, “A new look at the statistical model identification,” IEEE Trans. Autom. Control, Vol.19, pp. 716-723, 1974.
  23. [23] P. Wessel and W. H. F. Smith, “New, Improved version of the Generic Mapping Tools released,” EOS trans. AGU, Vol.79, p. 579, 1998.

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, IE9,10,11, Opera.

Last updated on Jan. 19, 2018