气候变化领域集成服务门户(CCPortal): Three-dimensional mechanical modeling of the GPS velocity field around the northeastern Tibetan plateau and surrounding regions

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DOI	10.1016/j.tecto.2012.03.025
	Three-dimensional mechanical modeling of the GPS velocity field around the northeastern Tibetan plateau and surrounding regions
	He, Jiankun; Lu, Shuangjiang; Wang, Weimin
通讯作者	He, JK (通讯作者)
发表日期	2013
ISSN	0040-1951
EISSN	1879-3266
起始页码	257
结束页码	266
卷号	584
英文摘要	The northeastern corner of the Tibetan plateau is a complex tectonic region with different fault mechanisms from left-lateral thrusting of the Qilian Shan, left-lateral strike slipping of the Haiyuan fault along the plateau edge, and right-lateral extension across the Alashan and the Ordos out of the northeastern Tibetan plateau. Here, we use 3D finite element models incorporating fault as Coulomb-type friction zone to investigate mechanical relation between crustal rheology and long-term deformation of the main active fault systems. Models are constrained with GPS velocity field and available geological slip rates. Crustal rheology is simplified as an elastobrittle upper part, underlying with viscoelastic crust. We test models with fault frictions (mu) from 0.4 to 0.02 on different fault systems, and mean viscosities (eta) of the lower crust from 10(19) Pa.s to 10(21) Pa.s in the Tibetan plateau and 10(21) Pa.s to 10(23) Pa.s out of the Tibetan plateau. A common feature from the numerical experiments is that the Haiyuan fault reflects a low fault friction (mu<0.1-0.08). The predicted low fault friction associated with the mean viscosities of the lower crust of similar to 10(19) Pa.s in the Tibetan plateau and similar to 10(21) Pa.s out of the Tibetan plateau can fit the geological slip rates well for the active faults. This suggests that slip partitioning around northeastern boundary of the Tibetan plateau is related mechanically to the low fault friction. Numerical experiments also show that after strain rates are absorbed by the main fault systems, the rest are strongly affected by crustal rheology. Finally, even the fault friction decreases to similar to 0.05, the mean viscosities of lower crust attain to 10(21) Pa.s and 10(23) Pa.s in and out of the Tibetan plateau, the northeastern Tibetan plateau and the Alashan still deforms diffusively, except that the Ordos behaves more like a rigid block. (C) 2012 Elsevier B.V. All rights reserved.
关键词	WESTERN HAIYUAN FAULT INDIA-ASIA COLLISION ACTIVE DEFORMATION QILIAN-SHAN SLIP RATE CRUSTAL DEFORMATION AUTONOMOUS REGION CHINA GANSU TECTONICS
英文关键词	Active tectonics; GPS; Mechanical modeling; Northeastern Tibetan plateau
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000315613700023
来源期刊	TECTONOPHYSICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258096
推荐引用方式 GB/T 7714	He, Jiankun,Lu, Shuangjiang,Wang, Weimin. Three-dimensional mechanical modeling of the GPS velocity field around the northeastern Tibetan plateau and surrounding regions[J]. 中国科学院青藏高原研究所,2013,584.
APA	He, Jiankun,Lu, Shuangjiang,&Wang, Weimin.(2013).Three-dimensional mechanical modeling of the GPS velocity field around the northeastern Tibetan plateau and surrounding regions.TECTONOPHYSICS,584.
MLA	He, Jiankun,et al."Three-dimensional mechanical modeling of the GPS velocity field around the northeastern Tibetan plateau and surrounding regions".TECTONOPHYSICS 584(2013).