气候变化领域集成服务门户(CCPortal): Segmentation of the Aleutian-Alaska Subduction Zone Revealed by Full-Wave Ambient Noise Tomography: Implications for the Along-Strike Variation of Volcanism

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DOI	10.1029/2020JB019677
	Segmentation of the Aleutian-Alaska Subduction Zone Revealed by Full-Wave Ambient Noise Tomography: Implications for the Along-Strike Variation of Volcanism
	Yang X.; Gao H.
发表日期	2020
ISSN	21699313
卷号	125 期号:11
英文摘要	The along-strike variations of the velocity, thickness, and dip of subducting slabs and the volcano distribution have been observed globally. It is, however, unclear what controls the distribution of volcanoes and the associated magma generation. With the presence of nonuniform volcanism, the Aleutian-Alaska subduction zone (AASZ) is an ideal place to investigate subduction segmentation and its relationship with volcanism. Using full-wave ambient noise tomography, we present a high-resolution 3-D shear wave velocity model of the AASZ for the depths of 15–110 km. The velocity model reveals the distinct high-velocity Pacific slab, the thicker, flatter, and more heterogeneous Yakutat slab, and the northeasterly dipping Wrangell slab. We observe low velocities within the uppermost mantle (at depth <60 km) below the Aleutian arc volcanoes, representing partial melt accumulation. The large crustal low-velocity anomaly beneath the Wrangell volcanic field suggests a large magma reservoir, likely responsible for the clustering of volcanoes. The Denali volcanic gap is above an average-velocity crust but an extremely fast mantle wedge, suggesting the lack of subsurface melt. This is in contrast with the lower-velocity back-arc mantle beneath the adjacent Buzzard Creek-Jumbo Dome volcanoes to the east. The back-arc low velocities associated with the Pacific, the eastern Yakutat, and the Wrangell slabs may reflect subduction-driven mantle upwelling. The structural variation of the downgoing slabs and the overriding plate explains the change of volcanic activity along the AASZ. Our findings demonstrate the combined role of the subducting slab and the overriding plate in controlling the characteristics of arc magmatism. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Aleutian-Alaska subduction zone; Denali volcanic gap; full-wave ambient noise tomography; mantle forearc serpentinization; subduction segmentation; volcanism in Alaska
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/187524
作者单位	Department of Geosciences, University of Massachusetts Amherst, Amherst, MA, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Now at Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, United States
推荐引用方式 GB/T 7714	Yang X.,Gao H.. Segmentation of the Aleutian-Alaska Subduction Zone Revealed by Full-Wave Ambient Noise Tomography: Implications for the Along-Strike Variation of Volcanism[J],2020,125(11).
APA	Yang X.,&Gao H..(2020).Segmentation of the Aleutian-Alaska Subduction Zone Revealed by Full-Wave Ambient Noise Tomography: Implications for the Along-Strike Variation of Volcanism.Journal of Geophysical Research: Solid Earth,125(11).
MLA	Yang X.,et al."Segmentation of the Aleutian-Alaska Subduction Zone Revealed by Full-Wave Ambient Noise Tomography: Implications for the Along-Strike Variation of Volcanism".Journal of Geophysical Research: Solid Earth 125.11(2020).