气候变化领域集成服务门户(CCPortal): Thermo-Mechanical Numerical Modeling of the South American Subduction Zone: A Multi-Parametric Investigation

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DOI	10.1029/2020JB021527
	Thermo-Mechanical Numerical Modeling of the South American Subduction Zone: A Multi-Parametric Investigation
	Strak V.; Schellart W.P.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	The South American subduction zone is enigmatic due to its fast subducting plate consumption, strong oscillation in subducting plate velocity, and deep mantle subduction. A key to help understand these subduction zone characteristics is through studying its dynamics with buoyancy-driven numerical modeling that uses independent variables to best approximate the dynamics of the real subduction system. We conduct a parametric investigation on the effect of upper mantle rheology, subduction interface yield stress and slab thermal weakening. To constrain those model variables, we attempt to find best-fits by comparing our model outcomes with the present-day slab geometry and estimates of Cenozoic velocities in the center of the South American subduction zone. Key ingredients that need to be reproduced are low slab dip angles close to the surface, steeper lower mantle dip angles, strong oscillation of the fast Farallon-Nazca subducting plate velocity and a progressive decrease in trench retreat rate during long-term subduction. We include these ingredients to define a model fitting score using 10 criteria. Our best fitting models involve a weak subduction zone interface (yield stress of ∼20 MPa) and significant slab thermal weakening to attain the fast Farallon-Nazca subducting plate velocity and to better reproduce the subduction partitioning since 48 Ma due to reduced shear stresses resisting downdip slab sinking and reduced slab bending resistance. Furthermore, a non-Newtonian upper mantle promotes slab folding and realistic oscillation of the subducting plate velocity. Whether and how this slab folding process induces temporal variations in Andean deformation remains an open question. © 2021. The Authors.
英文关键词	geodynamics; numerical modeling; South America; subduction
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187182
作者单位	Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
推荐引用方式 GB/T 7714	Strak V.,Schellart W.P.. Thermo-Mechanical Numerical Modeling of the South American Subduction Zone: A Multi-Parametric Investigation[J],2021,126(4).
APA	Strak V.,&Schellart W.P..(2021).Thermo-Mechanical Numerical Modeling of the South American Subduction Zone: A Multi-Parametric Investigation.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Strak V.,et al."Thermo-Mechanical Numerical Modeling of the South American Subduction Zone: A Multi-Parametric Investigation".Journal of Geophysical Research: Solid Earth 126.4(2021).