Rheological profile across the northeastern Japan lithosphere toward precise modeling of the 2011 Tohoku Oki Earthquake

• Muto Jun

  Department of Earth Sciences, Tohoku University

• Ohzono Mako

  Institute of Seismology and Volcanology, Hokkaido University

Bibliographic Information

Other Title

• 東日本太平洋沖地震後の余効変動解析へ向けた東北日本弧レオロジー断面
• ヒガシニホン タイヘイヨウオキ ジシン ゴ ノ ヨコウヘンドウ カイセキ エ ムケタ トウホク ニホン コ レオロジー ダンメン

Abstract

A two-dimensional rheological profile crossing the northeastern Japan arc was created to evaluate and distinguish various styles of post-seismic deformation relating to the 2011 Tohoku-Oki earthquake. The calculated profile is based on recent rock-mechanics studies and geophysical observations that explain observed patterns of geodetic strain accumulation and shallow seismicity prior to the earthquake. Viscosities were then calculated assuming stress-change magnitudes commonly associated with interplate earthquakes. Recently derived flow laws for various rocks and minerals predict the presence of weak zones that developed via processes likely operating in the lithosphere (e.g., partial melting and shear zone development). Strain localization into weak zones explains low viscosity estimates (10¹⁸—10²⁰ Pas) from post-seismic creep after inland earthquake events. Our calculations reveal significant lateral variations in strengths and viscosities across the northeastern Japan arc. These viscoelastic lithospheric structures should be taken into account in order to differentiate viscous relaxation from other post-seismic deformation processes.

Journal

• The Journal of the Geological Society of Japan

  The Journal of the Geological Society of Japan 118 (5), 323-333, 2012-05-15

  The Geological Society of Japan

Keywords

• Tohoku Oki Earthquake
• post-seismic
• deformation
• rheological profile
• viscoelastic relaxation
• northeastern Japan arc
• crustal structure

Details

• CRID: 1390001206240339712
• NII Article ID: 130002530854
• NII Book ID: AN00141768
• DOI: 10.5575/geosoc.2012.0026
• COI: 1:CAS:528:DC%2BC38XhtFWhurbJ
• ISSN: 13499963
• ISSN: 00167630
• NDL BIB ID: 023816656
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I023816656
• Web Site: https://www.jstage.jst.go.jp/article/geosoc/118/5/118_2012.0026/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed