Probability of a great earthquake to recur in the Tokai district, Japan: reevaluation based on newly-developed paleoseismology, plate tectonics, tsunami study, micro-seismicity and geodetic measurements

• Rikitake Tsuneji

  Association for the Development of Earthquake Prediction

抄録

In light of newly-acquired geophysical information about earthquake generation in the Tokai area, Central Japan, where occurrence of a great earthquake of magnitude 8 or so has recently been feared, probabilities of earthquake occurrence in the near future are reevaluated. Much of the data used for evaluation here relies on recently-developed paleoseismology, tsunami study and GPS geodesy. The new Weibull distribution analysis of recurrence tendency of great earthquakes in the Tokai-Nankai zone indicates that the mean return period of great earthquakes there is estimated as 109 yr with a standard deviation amounting to 33 yr. These values do not differ much from those of previous studies (Rikitake, 1976, 1986; Utsu, 1984). Taking the newly-determined velocities of the motion of Philippine Sea plate at various portions of the Tokai-Nankai zone into account, the ultimate displacements to rupture at the plate boundary are obtained. A Weibull distribution analysis results in the mean ultimate displacement amounting to 4.70 m with a standard deviation estimated as 0.86 m. A return period amounting to 117 yr is obtained at the Suruga Bay portion by dividing the mean ultimate displacement by the relative plate velocity. With the aid of the fault models as determined from the tsunami studies, the increases in the cumulative seismic slips associated with the great earthquakes are examined at various portions of the zone. It appears that a slip-predictable model can better be applied to the occurrence mode of great earthquakes in the zone than a time-predictable model. The crustal strain accumulating over the Tokai area as estimated from the newly-developed geodetic work including the GPS observations is compared to the ultimate strain presumed by the above two models. The probabilities for a great earthquake to recur in the Tokai district are then estimated with the aid of theWeibull analysis parameters obtained for the four cases discussed in the above. All the probabilities evaluated for the four cases take on values ranging 35-45 percent for a ten-year period following the year 2000.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 51 (3), 147-157, 1999

  地球電磁気・地球惑星圏学会 、公益社団法人 日本地震学会、特定非営利活動法人 日本火山学会、日本測地学会、日本惑星科学会

キーワード

• Space and Planetary Science
• Geology

詳細情報

• CRID: 1390001206508818048
• NII論文ID: 10003737410
• NII論文ID: 130003780739
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03352219
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 4716975
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4716975
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03352219.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03352219/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03352219
• 本文言語コード: en
• データソース種別:
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  • NDL
  • Crossref
  • CiNii Articles
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