DOI: 10.1002/2015GL066734
论文题名: Seismic anisotropy in the Earth's innermost inner core: Testing structural models against mineral physics predictions
作者: Romanowicz B. ; Cao A. ; Godwal B. ; Wenk R. ; Ventosa S. ; Jeanloz R.
刊名: Geophysical Research Letters
ISSN: 0094-9513
EISSN: 1944-9244
出版年: 2016
卷: 43, 期: 1 起始页码: 93
结束页码: 100
语种: 英语
英文关键词: elasticity of iron
; inner core anisotropy
Scopus关键词: Anisotropy
; Elasticity
; Forecasting
; Iron
; Seismology
; Single crystals
; Statistical tests
; Body-centered cubic
; Earth's rotation
; Inner core
; Mineral physics
; Seismic anisotropy
; Seismological data
; Structural models
; Travel time data
; Crystal structure
; crystal structure
; data set
; Earth rotation
; elasticity
; inner core
; iron
; seismic anisotropy
; seismology
; testing method
; travel time
; wave reflection
英文摘要: Using an updated data set of ballistic PKIKP travel time data at antipodal distances, we test different models of anisotropy in the Earth's innermost inner core (IMIC) and obtain significantly better fits for a fast axis aligned with Earth's rotation axis, rather than a quasi-equatorial direction, as proposed recently. Reviewing recent results on the single crystal structure and elasticity of iron at core conditions, we find that an hcp structure with the fast c axis parallel to Earth's rotation is more likely but a body-centered cubic structure with the [111] axis aligned in that direction results in very similar predictions for seismic anisotropy. These models are therefore not distinguishable based on current seismological data. In addition, to match the seismological observations, the inferred strength of anisotropy in the IMIC (6-7%) implies almost perfect alignment of iron crystals, an intriguing, albeit unlikely situation, especially in the presence of heterogeneity, which calls for further studies. © 2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84970897349&doi=10.1002%2f2015GL066734&partnerID=40&md5=1b5b4f4269a2c253423df44c9dd8a97a
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/10476
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: Department of Earth and Planetary Science, University of California, Berkeley, CA, United States
Recommended Citation:
Romanowicz B.,Cao A.,Godwal B.,et al. Seismic anisotropy in the Earth's innermost inner core: Testing structural models against mineral physics predictions[J]. Geophysical Research Letters,2016-01-01,43(1).