海溝型地震・津波発生における粘土鉱物の役割

DOI Web Site
  • 亀田 純
    北海道大学　大学院理学研究院地球惑星科学部門　地球惑星システム科学分野
  • 清水 麻由子
    日本原子力研究開発機構　バックエンド研究開発部門　東濃地科学センター地層科学研究部　ネオテクトニクス研究グループ

書誌事項

タイトル別名
  • Role of Clay Minerals on Tsunamigenic Faulting During Large Earthquakes
  • カイコウガタ ジシン ・ ツナミ ハッセイ ニ オケル ネンド コウブツ ノ ヤクワリ

この論文をさがす

説明

<p>The very large slip on the shallow portion of the subduction interface during the 2011 Tohoku-oki earthquake (Mw 9.0) caused a huge tsunami along the northeast coast of Honshu, Japan. In order to elucidate the mechanics of such tsunamigenic slip, the Integrated Ocean Drilling Program Expedition 343 (Japan Trench Fast Drilling Project, JFAST), was carried out one year after the earthquake and succeeded in recovering rocks constituting the active plate boundary fault. Mineralogical analyses using X-ray diffraction revealed that the shallow portion of the megathrust is significantly enriched in smectite (60-80wt.%) compared to the surrounding sediments. This mineralogical feature is a fundamental reason for realizing the weak fault zone under various slip conditions as demonstrated by laboratory friction experiments. The smectite-rich deposits are broadly distributed in the northwestern Pacific Ocean, and may therefore potentially enhance conditions for large shallow slip during earthquakes, which would result in large tsunamis for this region.</p>

収録刊行物

  • 粘土科学

    粘土科学 54 (3), 105-113, 2016

    一般社団法人 日本粘土学会

関連プロジェクト

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