| DOI: | 10.1002/grl.50372
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| 论文题名: | Sharp hemisphere boundaries in a translating inner core |
| 作者: | Geballe Z.M.; Lasbleis M.; Cormier V.F.; Day E.A.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9111
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| EISSN: | 1944-8842
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| 出版年: | 2013
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| 卷: | 40, 期:9 | | 起始页码: | 1719
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| 结束页码: | 1723
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| 语种: | 英语
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| 英文关键词: | grain growth
; hemisphere
; inner core
; translation
; velocity dispersion
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| Scopus关键词: | Anisotropic elasticity
; Crystalline domains
; hemisphere
; Inner core
; Inner core boundary
; Random distribution
; Seismic observation
; Velocity dispersion
; Anisotropy
; Elasticity
; Grain growth
; Seismic prospecting
; Translation (languages)
; Wave propagation
; Dispersions
; anisotropy
; forward modeling
; geodynamics
; inner core
; isotropy
; numerical model
; rigidity
; seismic velocity
; seismicity
; travel time
; wave velocity
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| 英文摘要: | Geodynamic models of a convectively translating inner core have recently been proposed that would account for the seismically observed differences in isotropic velocity between the eastern and western hemispheres of the inner core. These models, however, have previously been thought to be incompatible with seismic observations of a 1.5% P wave velocity change occurring over an 800 km wide region at the boundary between hemispheres of the inner core. Here we show that if rigid translation occurs, the age of material in the 100 km below the inner core boundary changes quickly as it crosses the boundary between the western and eastern hemispheres. We then forward model seismic traveltimes to show that the sharp transition in VP between hemispheres may be explained by a random distribution of highly oriented crystalline domains that grow during translation and are composed of material with relatively high elastic anisotropy (up to 12%). Key Points Sharp hemisphere boundaries in upper inner core are compatible with translationCertain model parameters reproduce seismic trends in isotropic Vp and QpTo match the 1.5% variation in Vp requires a highly anisotropic elasticity model ©2013. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879117862&doi=10.1002%2fgrl.50372&partnerID=40&md5=83338299ba40fa35faa8f39428abda81
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/6375
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| Appears in Collections: | 气候减缓与适应
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作者单位: | Department of Earth and Planetary Science, University of California Berkeley, Berkeley CA 94720, United States
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| Recommended Citation: | |
Geballe Z.M.,Lasbleis M.,Cormier V.F.,et al. Sharp hemisphere boundaries in a translating inner core[J]. Geophysical Research Letters,2013-01-01,40(9).
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