气候变化领域集成服务门户(CCPortal): Crustal Structure of the Northern Hikurangi Margin, New Zealand: Variable Accretion and Overthrusting Plate Strength Influenced by Rough Subduction

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DOI	10.1029/2020JB021176
	Crustal Structure of the Northern Hikurangi Margin, New Zealand: Variable Accretion and Overthrusting Plate Strength Influenced by Rough Subduction
	Gase A.C.; Van Avendonk H.J.A.; Bangs N.L.; Bassett D.; Henrys S.A.; Barker D.H.N.; Kodaira S.; Jacobs K.M.; Luckie T.W.; Okaya D.A.; Fujie G.; Yamamoto Y.; Arnulf A.F.; Arai R.
发表日期	2021
ISSN	21699313
卷号	126 期号:5
英文摘要	Exploring the structure of convergent margins is key to understanding megathrust slip behavior and tsunami generation. We present new wide-angle and marine multichannel seismic data that constrain the crustal structure and accretion dynamics of the northern Hikurangi margin. The top of the basement of the Hikurangi Plateau is overlain by a rough, 2–3 km thick layer of volcanic cover with P-wave velocities (VP) between 3 and 5 km/s. This volcanic cover contributes significantly to seismic reflectivity beneath the shallow subduction plate boundary. The frontal prism structure varies along-strike from ∼25 km wide with imbricate thrust faults where accretion of trench sediments is undisrupted, to narrower (∼14 km) with slumps and branching, irregular thrust fault geometries, which may reflect lower sediment supply or past seamount collisions. A large thrust fault network in the inner prism with a seismically fast hanging wall indicates a mechanical boundary between a seismically faster deforming backstop and the seismically slower frontal prism. Near the coastline, VP increases between 2.8 and 4 km/s at 2–8 km depth and is 0.5–1.7 km/s slower than the southern Hikurangi margin. Low seismic wavespeeds and low vertical velocity gradients in the inner prism support the hypothesis that a weak overthrusting plate contributes to historic tsunami-earthquakes and long duration seismic ground motion. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Hikurangi; low velocity; megathrust; seamount; subduction zone; upper plate
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/187136
作者单位	Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States; Department of Geosciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States; GNS Science, Lower Hutt, New Zealand; Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan; Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
推荐引用方式 GB/T 7714	Gase A.C.,Van Avendonk H.J.A.,Bangs N.L.,et al. Crustal Structure of the Northern Hikurangi Margin, New Zealand: Variable Accretion and Overthrusting Plate Strength Influenced by Rough Subduction[J],2021,126(5).
APA	Gase A.C..,Van Avendonk H.J.A..,Bangs N.L..,Bassett D..,Henrys S.A..,...&Arai R..(2021).Crustal Structure of the Northern Hikurangi Margin, New Zealand: Variable Accretion and Overthrusting Plate Strength Influenced by Rough Subduction.Journal of Geophysical Research: Solid Earth,126(5).
MLA	Gase A.C.,et al."Crustal Structure of the Northern Hikurangi Margin, New Zealand: Variable Accretion and Overthrusting Plate Strength Influenced by Rough Subduction".Journal of Geophysical Research: Solid Earth 126.5(2021).