DOI: 10.1016/j.epsl.2021.116785
论文题名: Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities
作者: Gama I. ; Fischer K.M. ; Eilon Z. ; Krueger H.E. ; Dalton C.A. ; Flesch L.M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 560 语种: 英语
中文关键词: Alaska Transportable Array
; Bayesian inversion
; lithosphere-asthenosphere boundary
; mantle imaging
; Sp receiver functions
英文关键词: Acoustic wave velocity
; Cluster analysis
; K-means clustering
; Lithology
; Phase velocity
; Plates (structural components)
; Rayleigh waves
; Shear waves
; Statistical tests
; Structural geology
; Time domain analysis
; Volcanoes
; Absolute velocities
; Continental lithosphere
; Lithosphere-asthenosphere boundary
; Lithospheric structure
; Lithospheric thickness
; Rayleigh surface waves
; Rayleigh-wave phase velocity
; Shear wave velocity structure
; Shear flow
; Bayesian analysis
; data inversion
; lithospheric structure
; numerical model
; Pacific plate
; plate motion
; plate tectonics
; Rayleigh wave
; S-wave
; seismic velocity
; velocity structure
; Alaska
; Denali Fault Zone
; United States
英文摘要: The present-day lithospheric structure of Alaska is the result of a unique tectonic history of subduction and terrane accretion that controls upper plate thickness and rheology. To provide new constraints on the structure of the crust and upper mantle beneath Alaska, we jointly inverted Sp receiver functions and Rayleigh wave phase velocities to calculate shear-wave velocity profiles. Robust Sp receiver functions were obtained using a broad range of frequencies (2–100 s), time-domain deconvolution, and K-means cluster analysis. Tests of the Bayesian joint inversion with synthetic data illustrate that Sp receiver functions enhance the resolution of the velocity gradients at the Moho and the lithosphere-asthenosphere boundary, while Rayleigh surface waves provide information about absolute velocities. Our results show that in central Alaska, above the shallow slab, the continental lithosphere is thinnest (∼60 km) and the asthenosphere has its lowest velocities. This zone coincides with the Denali Volcanic Gap. The continental lithosphere thickens to the north beneath the Brooks Range and the northern Arctic Alaska terrane, reaching values of 110 to 130 km, with high lithospheric velocities that are comparable to Archean cratons. This pattern is consistent with a northward decrease in upper plate modification by melt and volatiles derived from the slab, in addition to intrinsic mantle velocity and viscosity differences between inherited lithospheric terranes. Lithospheric and asthenospheric velocities are not significantly different inside and outside of the Denali Volcanic Gap, but at the boundaries of this region lithospheric thickness increases rapidly to the north and gradually to the south. In the south, the subducting Yakutat plate is thicker (∼100–120 km) than the subducting Pacific plate (∼80–90 km), likely due to its thicker crust. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165472
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, United States; Department of Earth Sciences, University of California, Santa Barbara, CA 93106, United States; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, United States
Recommended Citation:
Gama I.,Fischer K.M.,Eilon Z.,et al. Shear-wave velocity structure beneath Alaska from a Bayesian joint inversion of Sp receiver functions and Rayleigh wave phase velocities[J]. Earth and Planetary Science Letters,2021-01-01,560