DOI: 10.1016/j.epsl.2017.12.011
Scopus记录号: 2-s2.0-85038217005
论文题名: The lithosphere–asthenosphere boundary beneath the South Island of New Zealand
作者: Hua J. ; Fischer K.M. ; Savage M.K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 484 起始页码: 92
结束页码: 102
语种: 英语
英文关键词: Alpine fault
; lithosphere–asthenosphere boundary
; New Zealand
Scopus关键词: Metamorphic rocks
; Plates (structural components)
; Seismology
; Surface waves
; Alpine Faults
; Common-conversion points
; New zealand
; Oceanic lithosphere
; Receiver functions
; Strike-slip deformation
; Surface-wave tomography
; Three dimensional space
; Laboratories
; asthenosphere
; Australian plate
; deconvolution
; deformation
; lithospheric structure
; Pacific plate
; plate boundary
; seismic tomography
; seismic velocity
; seismology
; strike-slip fault
; subduction zone
; transpression
; New Zealand
; South Island
英文摘要: Lithosphere–asthenosphere boundary (LAB) properties beneath the South Island of New Zealand have been imaged by Sp receiver function common-conversion point stacking. In this transpressional boundary between the Australian and Pacific plates, dextral offset on the Alpine fault and convergence have occurred for the past 20 My, with the Alpine fault now bounded by Australian plate subduction to the south and Pacific plate subduction to the north. Using data from onland seismometers, especially the 29 broadband stations of the New Zealand permanent seismic network (GeoNet), we obtained 24,971 individual receiver functions by extended-time multi-taper deconvolution, and mapped them to three-dimensional space using a Fresnel zone approximation. Pervasive strong positive Sp phases are observed in the LAB depth range indicated by surface wave tomography. These phases are interpreted as conversions from a velocity decrease across the LAB. In the central South Island, the LAB is observed to be deeper and broader to the northwest of the Alpine fault. The deeper LAB to the northwest of the Alpine fault is consistent with models in which oceanic lithosphere attached to the Australian plate was partially subducted, or models in which the Pacific lithosphere has been underthrust northwest past the Alpine fault. Further north, a zone of thin lithosphere with a strong and vertically localized LAB velocity gradient occurs to the northwest of the fault, juxtaposed against a region of anomalously weak LAB conversions to the southeast of the fault. This structure could be explained by lithospheric blocks with contrasting LAB properties that meet beneath the Alpine fault, or by the effects of Pacific plate subduction. The observed variations in LAB properties indicate strong modification of the LAB by the interplay of convergence and strike-slip deformation along and across this transpressional plate boundary. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110063
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Dept. of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, United States; Institute of Geophysics, Victoria University of Wellington, Wellington, New Zealand
Recommended Citation:
Hua J.,Fischer K.M.,Savage M.K.. The lithosphere–asthenosphere boundary beneath the South Island of New Zealand[J]. Earth and Planetary Science Letters,2018-01-01,484