- Research News
- Open Access
Two grave issues concerning the expected Tokai Earthquake
Earth, Planets and Space volume 56, pagesli–lxvi(2004)
The possibility of a great shallow earthquake (M 8) in the Tokai region, central Honshu, in the near future was pointed out by Mogi in 1969 and by the Coordinating Committee for Earthquake Prediction (CCEP), Japan (1970). In 1978, the government enacted the Large-Scale Earthquake Countermeasures Law and began to set up intensified observations in this region for short-term prediction of the expected Tokai earthquake. In this paper, two serious issues are pointed out, which may contribute to catastrophic effects in connection with the Tokai earthquake: 1. The danger of black-and-white predictions: According to the scenario based on the Large-Scale Earthquake Countermeasures Law, if abnormal crustal changes are observed, the Earthquake Assessment Committee (EAC) will determine whether or not there is an imminent danger. The findings are reported to the Prime Minister who decides whether to issue an official warning statement. Administrative policy clearly stipulates the measures to be taken in response to such a warning, and because the law presupposes the ability to predict a large earthquake accurately, there are drastic measures appropriate to the situation. The Tokai region is a densely populated region with high social and economic activity, and it is traversed by several vital transportation arteries. When a warning statement is issued, all transportation is to be halted. The Tokyo capital region would be cut off from the Nagoya and Osaka regions, and there would be a great impact on all of Japan. I (the former chairman of EAC) maintained that in view of the variety and complexity of precursory phenomena, it was inadvisable to attempt a black-and-white judgment as the basis for a “warning statement”. I urged that the government adopt a “soft warning” system that acknowledges the uncertainty factor and that countermeasures be designed with that uncertainty in mind. 2. The danger of nuclear power plants in the focal region: Although the possibility of the occurrence of a great shallow earthquake in the Tokai region was pointed out by CCEP in 1970, soon after, plans for construction of a nuclear power plant started in this region. Since 1976, Hamaoka nuclear power plants (Units 1∼4) have been operating near the center of the expected focal region of the great Tokai earthquake, and Unit 5 is under construction. This is quite a dangerous situation.
Agency of Natural Resources and Energy, Sites of nuclear power plants in Japan, pp. 26, 2002 (in Japanese).
Central Disaster Management Council, Report on the Tokai Earthquake by Organization for Technical Investigation in Central Disaster Management Council in 2001, 2001.
Central Disaster Management Council, Report on the Tokai Earthquake by Organization for Technical Investigation in Central Disaster Management Council in 2002, 2002.
Coordinating Committee for Earthquake Prediction, Designation of Areas of Specific Observation, Report of Coordinating Committee for earthquake Prediction, 3, 89–91, 1970.
Federation of Electric Power Companies of Japan, Home page from FEPC, www.fepc-atomic.jp, 2000.
Geographical Survey Institute, Japan, Vertical movements in Tokai district, Report of Coordinating Committee for Earthquake Prediction, 2, 49–53, 1970 (in Japanese).
Geographical Survey Institute, Japan, Vertical movements in Tokai district (2), Report of Coordination Committee, 11, 102–104, 1974 (in Japanese).
Geographical Survey Institute, Japan, Horizontal displacements observed by GPS (1998–1999) in and around the Tokai region, personal communication, 2003.
Hagiwara, T., Distribution of Seismic Intensity in 1854 Tokai earthquake, Report of Coordinating Committee for Earthquake Prediction, 3, 51–52, 1970 (in Japanese).
Harada, K. and N. Isawa, Horizontal deformation of the crust in Japan—Result obtained by multiple fixed stations, J. Geodetic Soc. Japan, 14, 101–105, 1969.
Ishibashi, K., Re-examination of a great earthquake expected in the Tokai district: Possibility of the ‘Suruga Bay earthquake’, Abstracts, Seismol. Soc. Japan 1976, No. 2, 30–34, 1976 (in Japanese).
Ishibashi, K., Genpatsu-shinsai, Kagaku, 67, 720–724, 1997 (in Japanese).
Japan Atomic Industrial Forum, Generating capacity of nuclear power plants in the world, Nuclear Power Plants in the World, Tokyo, 195 pp, 2002.
Kasahara, K. and A. Sugimura, Spatial distribution of horizontal secular strain in Japan, J. Geodedic Soc. Japan, 10, 139–145, 1964.
Komura, H., Tokai earthquake and Hamaoka nuclear power plants, Kagaku, 51, 449–457, 1981 (in Japanese).
Land Agency, Earthquake Countermeasures in Japan, 1987.
Mogi, K., Recent horizontal deformation of the earth’s crust and tectonic activity in Japan (1), Bull. Earthq. Res. Inst., Univ. of Tokyo, 48, 413–430; Seismological interpretation of recent horizontal deformation of the earth’s crust in western Japan, Report of Coordinating Committee for Earthquake prediction, 2, 85-88, 1970 (in Japanese).
Mogi, K., Temporal variation of crustal deformation during the days preceding a thrust-type great earthquake—The 1944 Tonankai earthquake of magnitude 8.1, Japan, Pageoph, 122, 765–780, 1985.
Mogi, K., Earthquake prediction problem in the Tokai region, Proc. of Earthquake Prediction Research Symposium, 279–284, National Committee for Seismology, Science Council of Japan and Seismological Soc. of Japan, 1987 (in Japanese).
Mogi, K., Need of reexamination of the Tokai earthquake countermeasure, This is Yomiuri, Oct. 1996, 68–77, 1996 (in Japanese).
Mogi, K., Reexamination of the Tokai earthquake countermeasure, Zisin Journal, 32, 1–7, 2001a (in Japanese).
Mogi, K., Zishin no Hanashi (Stories of Earthquakes), Tokyo, Asakura Shoten, 150 pp, 2001b (in Japanese).
Mogi, K., Hamaoka nuclear power accident and earthquakes, Rondan, Nov. 13, 2001, Shizuoka Shinbun, 2001c (in Japanese).
Nakajima, T., Arguments for and against the nuclear power generation, Heibonsha Encyclopedia, 5, 117–122, 1984 (in Japanese).
Utsu, T., Seismicity Studies: A Comprehensive Review, Tokyo, 876 pp (see page 791), Univ. of Tokyo Press, 1999 (in Japanese).
Utsu, T., Catalog of Damaging Earthquakes in the World (through 2002), http://iisee.kenken.go.jp/utsu/index eng, 2002.
Working Group on California Earthquake Probabilities, Seismic hazards in Southern California: Probable earthquakes, 1994–2024, Bull. Seismol. Soc. Am., 85, 379–439, 1995.
About this article
Cite this article
Mogi, K. Two grave issues concerning the expected Tokai Earthquake. Earth Planet Sp 56, li–lxvi (2004) doi:10.1186/BF03353074
- Earthquake Countermeasures Law
- precursory phenomena
- black-and-white prediction
- soft warning
- Hamaoka nuclear power plant
- man-made disaster