Rapid mantle flow with power-law creep explains deformation after the 2011 Tohoku mega-quake

Ryoichiro Agata, Sylvain D. Barbot, Kohei Fujita, Mamoru Hyodo, Takeshi Iinuma, Ryoko Nakata, Tsuyoshi Ichimura, Takane Hori

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

The deformation transient following large subduction zone earthquakes is thought to originate from the interaction of viscoelastic flow in the asthenospheric mantle and slip on the megathrust that are both accelerated by the sudden coseismic stress change. Here, we show that combining insight from laboratory solid-state creep and friction experiments can successfully explain the spatial distribution of surface deformation in the first few years after the 2011 M w 9.0 Tohoku-Oki earthquake. The transient reduction of effective viscosity resulting from dislocation creep in the asthenosphere explains the peculiar retrograde displacement revealed by seafloor geodesy, while the slip acceleration on the megathrust accounts for surface displacements on land and offshore outside the rupture area. Our results suggest that a rapid mantle flow takes place in the asthenosphere with temporarily decreased viscosity in response to large coseismic stress, presumably due to the activation of power-law creep during the post-earthquake period.

Original languageEnglish
Article number1385
JournalNature communications
Volume10
Issue number1
DOIs
Publication statusPublished - 2019 Dec 1

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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