文章基本信息

标题：Short wavelength topography on the inner-core boundary
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作者：Aimin Cao ; Yder Masson ; Barbara Romanowicz 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2007
卷号：104
期号：1
页码：31-35
DOI：10.1073/pnas.0609810104
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Constraining the topography of the inner-core boundary is important for studies of core-mantle coupling and the generation of the geodynamo. We present evidence for significant temporal variability in the amplitude of the inner core reflected phase PKiKP for an exceptionally high-quality earthquake doublet, observed postcritically at the short-period Yellowknife seismic array (YK), which occurred in the South Sandwich Islands within a 10-year interval (1993/2003). This observation, complemented by data from several other doublets, indicates the presence of topography at the inner-core boundary, with a horizontal wavelength on the order of 10 km. Such topography could be sustained by small-scale convection at the top of the inner core and is compatible with a rate of super rotation of the inner core of {approx}0.1-0.15{degrees} per year. In the absence of inner-core rotation, decadal scale temporal changes in the inner-core boundary topography would provide an upper bound on the viscosity at the top of the inner core.
关键词：PKiKP ; super rotation ; doublet