Subduction-induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling

doi:10.1002/2014JB010996

	Subduction-induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling
	Li, Zhong-Hai 4; Di Leo, Jeanette F.; Ribe, Neil M.
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2014
卷号	119 期号:6 页码:5052-5076
ISSN号	2169-9313
DOI	10.1002/2014JB010996
英文摘要	Surface measurements of shear wave splitting patterns are widely used to infer the mantle circulation around subducting slabs; however, the relation between mantle flow and seismic anisotropy is still elusive. Finite strain is a direct measurement of time-dependent deformation and has been proposed as a proxy for the crystal-preferred orientation (CPO) of mantle minerals. We have conducted a series of numerical models to systematically investigate the mantle flow, finite strain, olivine CPO, and SKS wave splitting in oceanic subduction zones with variable slab width. They demonstrate that the preferred orientations of olivine a axes generally agree with the long (extensional) axes of the finite strain ellipsoid (FSE), even in these very complex mantle flow fields; however, neither the a axis nor the FSE axes necessarily aligns with the instantaneous mantle velocity vector. We identify two domains with distinct deformation mechanisms in the central subplate mantle, where simple shear induced by plate advance dominates at shallow depths and produces trench-normal fast splitting, while pure shear induced by slab rollback dominates the deeper mantle and results in trench-parallel fast splitting. The SKS splitting patterns are thus dependent on the competing effects of these two mechanisms and also on the subduction partition ratio gamma = X-p/X-t : trench parallel when gamma < 1 and trench normal when gamma > 1. In addition, different mantle deformation mechanisms and SKS splitting patterns are observed in the mantle wedge and around the slab edges, which may aid in the general interpretation of seismic anisotropy observations in natural subduction zones.
学科主题	构造地质学
WOS关键词	LATTICE-PREFERRED ORIENTATION ; TRENCH-PARALLEL FLOW ; SHEAR-WAVE ; UPPERMOST MANTLE ; PLASTIC-DEFORMATION ; ZONE ANISOTROPY ; PLATE MOTIONS ; NEW-ZEALAND ; BACK-ARC ; OLIVINE
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000339711000031
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40544]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, State Key Lab Continental Tecton & Dynam, Beijing, Peoples R China 2.[Di Leo, Jeanette F.] Univ Bristol, Sch Earth Sci, Bristol, Avon, England 3.[Ribe, Neil M.] Univ Paris 11, CNRS, UPMC, Lab FAST, F-91405 Orsay, France 4.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Li, Zhong-Hai,Di Leo, Jeanette F.,Ribe, Neil M.. Subduction-induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2014,119(6):5052-5076.
APA	Li, Zhong-Hai,Di Leo, Jeanette F.,&Ribe, Neil M..(2014).Subduction-induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,119(6),5052-5076.
MLA	Li, Zhong-Hai,et al."Subduction-induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 119.6(2014):5052-5076.