Seismic evidence for high pore pressures in the oceanic crust: Implications for fluid‐related embrittlement

DOI Web Site Web Site 被引用文献16件 参考文献29件 オープンアクセス
  • Takahiro Shiina
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science Tohoku University Sendai  980‐8578 Japan
  • Junichi Nakajima
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science Tohoku University Sendai  980‐8578 Japan
  • Toru Matsuzawa
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science Tohoku University Sendai  980‐8578 Japan

書誌事項

公開日
2013-05-28
資源種別
journal article
権利情報
  • http://onlinelibrary.wiley.com/termsAndConditions#vor
DOI
  • 10.1002/grl.50468
公開者
American Geophysical Union (AGU)

この論文をさがす

説明

<jats:title>Abstract</jats:title><jats:p>We estimated the <jats:italic>P</jats:italic> wave velocity structure of the crust of the subducting Pacific plate beneath northeast Japan using arrival time data of <jats:italic>P</jats:italic>‐to‐<jats:italic>S</jats:italic>‐converted waves. The results show that the <jats:italic>P</jats:italic> wave velocity of the subducting crust varies along the arc and increases abruptly at a depth of ~100 km, from 6.5–7.0 km/s in the fore arc to 7.5–8.5 km/s in the back arc. The <jats:italic>P</jats:italic> wave velocity in the fore arc is ~10% lower than theoretically expected values for the metamorphosed mid‐ocean ridge basalt material. Seismicity in the subducting crust is most active at depths of 70–80 km where <jats:italic>P</jats:italic> wave velocities are lowest. The marked reduction of <jats:italic>P</jats:italic> wave velocity suggests the coexistence of aqueous fluids with hydrous minerals. Abundant fluids elevate pore fluid pressures and reduce effective normal stress, promoting intensive seismic activity in the low‐velocity crust. Our observations provide seismic evidence that earthquakes in the subducting crust are facilitated by fluid‐related embrittlement.</jats:p>

収録刊行物

被引用文献 (16)*注記

もっと見る

参考文献 (29)*注記

もっと見る

関連プロジェクト

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ