日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 H (地球人間圏科学) » H-CG 地球人間圏科学複合領域・一般

[H-CG30] 内陸地震と原子力発電所の安全性

2019年5月26日(日) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:末次 大輔(海洋研究開発機構 地球深部ダイナミクス研究分野)、金嶋 聰(九州大学大学院理学研究院地球惑星科学部門)、鷺谷 威(名古屋大学減災連携研究センター)、寿楽 浩太(東京電機大学工学部人間科学系列)

[HCG30-P01] Lessons from recent inland earthquakes in the Japan Islands

*鷺谷 威1 (1.名古屋大学減災連携研究センター)

キーワード:地震ハザード、日本列島、内陸地震

Large earthquakes occurring inland are highly disastrous compared with their magnitude. In Japan, the 1995 Kobe Earthquake demonstrated how much tremendous damage such earthquakes could cause. Following this disaster, the Japanese government established the Headquarters for Earthquake Research Promotion (HERP) to promote investigation of earthquake research, including extensive investigation of active faults, for the purpose of better understand potential seismic hazard throughout the country. The achievements of HERP is summarized as the “Seismic hazard maps for Japan”, first published in 2005 and has been updated almost every year. In spite of such an effort, however, recent large earthquakes indicate that our knowledge about seismic hazard is still limited and thus our preparation is never complete. On 6 September 2018, a Mw6.6 earthquake occurred in the Iburi district of Hokkaido, named as the 2018 Eastern Iburi earthquake. The focal depth of this earthquake was 37 km. The largest intensity was JMA intensity VII and the observed largest acceleration was 1505 gal. 41 people were killed mainly due to landslides and liquefaction occurred over a wide area including a part of Tomakomai and Sapporo. Considering the earthquake magnitude and its focal depth, there was no surface rupture and active fault investigation is of no use to identify the potential of this earthquake. It is important to point out that even an earthquake of this size with the focal depth of 37 km can still cause such strong shaking. Evaluation of seismic potential and its possible disastrous consequences should be considered in the light of new seismic observations.