Crustal Deformation and Shallow Seismic Activity beneath the Northeastern Japan Arc

DOI IR HANDLE Web Site Web Site 12 Citations 46 References
  • HASEGAWA Akira
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University
  • NAKAJIMA Junichi
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University
  • UMINO Norihito
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University
  • MIURA Satoshi
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University
  • SUWA Yoko
    Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University

Bibliographic Information

Other Title
  • 東北日本弧における地殻の変形と内陸地震の発生様式
  • トウホク ニホン コ ニ オケル チカク ノ ヘンケイ ト ナイリク ジシン ノ ハッセイ ヨウシキ

Search this article

Abstract

Seismic tomography studies in northeastern (NE) Japan have revealed the existence of inclined seismic low-velocity zones at depths shallower than -150km in the mantle wedge sub-parallel to the subducted slab, which probably correspond to the upwelling flow portion of the subduction-induced convection. The inclined low-velocity zone attains the Moho right beneath the volcanic front or the Ou Backbone Range, suggesting that the volcanic front is formed by this hot upwelling flow. Aqueous fluids supplied from the suducted slab are transported upward through this upwelling flow, and thus reach to shallow levels along the Backbone Range. They are expelled from solidified magma and further migrate upward. Existence of aqueous fluids perhaps weakens the strength of the crustal rocks surrounding them. It is expected that this causes contractive deformation locally concentrated along the Backbone Range under the compressional stress field in this volcanic arc. A strain rate distribution map estimated from GPS data shows notable concentration of east-west contraction along the Backbone Range, consistent with the above expectation. Based on these observations, we propose a simple model to explain the deformation pattern of the arc crust and the characteristic shallow seismic activity beneath NE Japan.

Journal

Citations (12)*help

See more

References(46)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top