气候变化领域集成服务门户(CCPortal): Complex upper mantle anisotropy in the Pacific Northwest: Evidence from SKS splitting

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DOI	10.1016/j.epsl.2020.116264
	Complex upper mantle anisotropy in the Pacific Northwest: Evidence from SKS splitting
	Niday W.; Humphreys E.
发表日期	2020
ISSN	0012821X
卷号	540
英文摘要	We use a dense network of observations and an automated method of analysis to investigate complex patterns of seismic anisotropy in the Pacific Northwest. We present SKS splitting results for approximately 220 broadband seismic stations, including 33 stations from the new Wallowa2 array deployed between 2016 and 2018 in northeast Oregon. Our data set contains approximately 3300 splitting measurements. Our anisotropy measurements indicate that anisotropy in the Pacific Northwest can be divided into two domains: near the subduction zone, anisotropy is perpendicular to the slab; and inboard of the subduction zone anisotropy tends to parallel the velocity structure and is roughly oriented with “absolute” plate motion. However, splitting analysis performs poorly in northeast Oregon, and results are not consistent with uniform or layered anisotropy. We argue that the complex splitting behavior in northern Oregon is a result of spatially variable upper mantle anisotropy, related to the complex upper mantle seismic structure. Interpreting the mantle anisotropy in this region requires methods not limited to standard ray theoretical shear wave splitting analysis. © 2020 Elsevier B.V.
关键词	asthenosphere Pacific Northwest seismic anisotropy shear wave splitting
英文关键词	Complex networks; Seismology; Shear flow; Shear waves; Structural geology; Anisotropy measurements; Automated methods; Broad-band seismic stations; Seismic anisotropy; Shear wave splitting; Splitting measurements; Upper mantle anisotropy; Velocity structure; Anisotropy; automation; body wave; complexity; mantle structure; seismic anisotropy; upper mantle; velocity structure; wave splitting; Oregon; Pacific Ocean; Pacific Ocean (Northwest); United States
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202805
作者单位	Department of Earth Sciences, University of Oregon, Eugene, OR 97403-1272, United States
推荐引用方式 GB/T 7714	Niday W.,Humphreys E.. Complex upper mantle anisotropy in the Pacific Northwest: Evidence from SKS splitting[J],2020,540.
APA	Niday W.,&Humphreys E..(2020).Complex upper mantle anisotropy in the Pacific Northwest: Evidence from SKS splitting.Earth and Planetary Science Letters,540.
MLA	Niday W.,et al."Complex upper mantle anisotropy in the Pacific Northwest: Evidence from SKS splitting".Earth and Planetary Science Letters 540(2020).