DOI: 10.1038/ngeo1813
论文题名: The shuffling rotation of the Earth's inner core revealed by earthquake doublets
作者: Tkalčić H. ; Young M. ; Bodin T. ; Ngo S. ; Sambridge M.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 6 起始页码: 497
结束页码: 502
语种: 英语
Scopus关键词: Earth rotation
; geodynamics
; inner core
; inverse analysis
; mantle
; numerical model
; reconstruction
; seismic wave
; waveform analysis
; Alaska
; United States
英文摘要: Geodynamical models and seismic observations suggest that the Earth's solid inner core rotates at a different rate than the mantle. However, discrepancies exist in rotation rate estimates based on seismic waves produced by earthquakes. Here we investigate the inherent assumption of a constant rotation rate using earthquake doublets - repeating earthquakes that produce similar waveforms. We detect that the rotation rate of the Earth's inner core with respect to the mantle varies with time. We perform an inverse analysis of 7 doublets observed at the College station, Alaska, as well as 17 previously reported doublets, and reconstruct a history of differential inner-core rotation between 1961 and 2007. We find that the observed doublets are consistent with a model of an inner core with an average differential rotation rate of 0.25-0.48° yr-1 and decadal fluctuations of the order of 1° yr-1 around the mean. The decadal fluctuations explain discrepancies between previous core rotation models and are in concordance with recent geodynamical simulations. © 2013 Macmillan Publishers Limited. All rights reserved.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106782
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia; Berkeley Seismological Laboratory, University of California at Berkeley, Berkeley, CA 94720, United States
Recommended Citation:
Tkalčić H.,Young M.,Bodin T.,et al. The shuffling rotation of the Earth's inner core revealed by earthquake doublets[J]. Nature Geoscience,2013-01-01,6(6)