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ID 30897
本文ファイル
著者
Tagawa, Michio
Iwase, Yasuyuki
キーワード
Stagnant slab
Subduction
Mantle convection
Rheology
Numerical modeling
NDC
地球科学・地学・地質学
抄録(英)
We performed a numerical study to understand the dynamical mechanism controlling the formation and avalanche of a stagnant slab using two-dimensional dynamical models of the integrated plate-mantle system with freely movable subducting and overriding plates. We examined slab rheology as a mechanism for producing various styles of stagnating or penetrating slabs that interact with the 410-km and 660-km phase transitions. The simulated results with the systematically changed rheological parameters are interpreted using a simple stability analysis that includes the forces acting on the stagnant slab. Slab plasticity that memorizes the shape produced by past deformation generates slab stagnation at various depths around the 660-km phase transition. The slab stagnates even beneath the 660-km phase boundary, with a gentle Clapeyron slope. Feedbacks between trench backward migration and slab deformation promote each other during the slab stagnation stage. Slab viscosity also determines the final state of the subducted slab, that is, it continues stagnation or initiates penetration. A low viscosity slab can finally penetrate into the lower mantle because the growth time of the Rayleigh–Taylor instability is shorter. After the avalanche, the direction of the trench migration changes depending on the lower mantle slab viscosity.
掲載誌名
Physics of the Earth and Planetary Interiors
183巻
1-2号
開始ページ
309
終了ページ
320
出版年月日
2010-11
出版者
Elsevier Science BV
ISSN
0031-9201
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright (c) 2010 Published by Elsevier B.V.
関連情報URL
部局名
理学研究科