活断層のトレンチ調査結果を用いて推定した日本の内陸地震の長期危険度評価

DOI Web Site Web Site 被引用文献15件

書誌事項

タイトル別名
  • Long-Term Conditional Seismic Hazard of Quaternary Active Faults in Japan
  • カツダンソウ ノ トレンチ チョウサ ケッカ オ モチイテ スイテイ シタ ニ
  • 特集: 大地震の長期予測はどこまで可能か? I. 古地震調査と長期予測

この論文をさがす

抄録

The aim of this study is to show the long-term conditional (time-dependent) seismic hazard assessment of intraplate earthquakes in Japan. Two types of hazard assessment maps are illustrated by the combination of statistical method, long historical earthquake records, and the results of trenching surveys: one is the probability map of 0.2 g between 2001 and 2100 A.D., and the other is the peak horizontal ground acceleration (PGA) map of 10% chance including the effect of attenuation of surface geology during the same period. Although the number of trenching results with three or more events are only nine as of 1994 and the error of the data is large, the results still enable us to describe that (1) the compilation of the paleoearthquake results indicate that the recurrence interval of each fault seems to be quasi-periodic than random, and (2) the entire length of fault system does not always rupture together. This is important for seismic hazard assessments because the size and the frequency of earthquakes vary as a function of fault length. Earthquake statistics is then applied to the results of trenching surveys in order to calculate the conditional probabilities of active faults. For each trenching study site on a fault, I calculate the average recurrence interval, Tave. between events and then determine the ratios of the recurrence interval for specific event, T, pairs to Tave. The resulting distribution of T/Tave measurements are the basis to determine Weibull probability density function. The initial analysis suggest that the application of conditional estimates on specific faults is advantageous over the assumption of random process. The resulting maps show better agreement with the current understanding of recurrence cycle of active fault that, (1) low probabilities are obtained for faults that are considered to have ruptured in historical period, and (2) higher probabilities are calculated on faults with long elapsed time or high slip rate. Regarding the PGA map, the 0.5 g or higher are calculated at plains and basins bounded by the active fault with high probability, especially on the Median tectonic line, the Itoigawa-Shizuoka tectonic line, the Inadani fault system, the Kozu-Matsuda fault system, and the Beppu-Haneyama fault system. The maps are preliminary and will be modified by including the future paleoearthquake results.

収録刊行物

  • 地震　第２輯

    地震　第２輯 50 (appendix), 53-71, 1998

    公益社団法人 日本地震学会

被引用文献 (15)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ