DOI: 10.1002/2015GL064326
论文题名: The existence of radial anisotropy in Earth's upper inner core revealed from seismic normal mode observations
作者: Lythgoe K.H. ; Deuss A.
刊名: Geophysical Research Letters
ISSN: 0094-8672
EISSN: 1944-8403
出版年: 2015
卷: 42, 期: 12 起始页码: 4841
结束页码: 4848
语种: 英语
英文关键词: Earth's inner core
; normal modes
; radial anisotropy
Scopus关键词: Coremaking
; Seismology
; Solidification
; Anisotropic growth
; Center frequency
; Earth structures
; Earth's inner cores
; Inner core boundary
; Normal modes
; Radial anisotropy
; Solidification process
; Anisotropy
; anisotropy
; body wave
; Earth structure
; frequency analysis
; inner core
; isotropy
; outer core
; solidification
; sphere
; symmetry
; uncertainty analysis
英文摘要: As we strive to understand the most remote region of our planet, one critical area of investigation is the uppermost inner core since its structure is related to solidification of outer core material at the inner core boundary (ICB). Previous seismic studies have used body waves to show that the top ∼100 km of the inner core is isotropic. However, radial anisotropy cannot be uniquely determined by body wave observations. Alternatively, normal mode center frequencies are sensitive to spherically symmetric Earth structure, therefore may provide a constraint on the existence of radial anisotropy in the inner core. Here we show that normal mode center frequency measurements are compatible with 2-5% radial anisotropy in the top ∼100 km of the inner core with a fast direction radially outward and a slow direction along the ICB. Given the uncertainties in the mineral physics and processes that produce anisotropy, the observed radial anisotropy may be reconciled with predictions based on either solidification processes or from texturing due to anisotropic growth. © 2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948649787&doi=10.1002%2f2015GL064326&partnerID=40&md5=bc38e6c678cde0697917a25a1e8de785
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/8288
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Bullard Laboratories, University of Cambridge, Cambridge, United Kingdom
Recommended Citation:
Lythgoe K.H.,Deuss A.. The existence of radial anisotropy in Earth's upper inner core revealed from seismic normal mode observations[J]. Geophysical Research Letters,2015-01-01,42(12).