| DOI: | 10.1038/ngeo2709
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| 论文题名: | Global dynamic topography observations reveal limited influence of large-scale mantle flow |
| 作者: | Hoggard M.J.; White N.; Al-Attar D.
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| 刊名: | Nature Geoscience
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| ISSN: | 17520894
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| 出版年: | 2016
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| 卷: | 9, 期:6 | | 起始页码: | 456
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| 结束页码: | 463
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| 语种: | 英语
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| Scopus关键词: | amplitude
; benchmarking
; database
; density
; displacement
; mantle process
; oceanic circulation
; seismic survey
; spectral analysis
; topography
; wavelength
|
| 英文摘要: | Convective circulation of the Earth's mantle maintains some fraction of surface topography that varies with space and time. Most predictive models show that this dynamic topography has peak amplitudes of about ±2 km, dominated by wavelengths of 10 4 km. Here, we test these models against our comprehensive observational database of 2,120 spot measurements of dynamic topography that were determined by analysing oceanic seismic surveys. These accurate measurements have typical peak amplitudes of ±1 km and wavelengths of approximately 10 3 km, and are combined with limited continental constraints to generate a global spherical harmonic model, the robustness of which has been carefully tested and benchmarked. Our power spectral analysis reveals significant discrepancies between observed and predicted dynamic topography. At longer wavelengths (such as 10 4 km), observed dynamic topography has peak amplitudes of about ±500 m. At shorter wavelengths (such as 10 3 km), significant dynamic topography is still observed. We show that these discrepancies can be explained if short-wavelength dynamic topography is generated by temperature-driven density anomalies within a sub-plate asthenospheric channel. Stratigraphic observations from adjacent continental margins show that these dynamic topographic signals evolve quickly with time. More rapid temporal and spatial changes in vertical displacement of the Earth's surface have direct consequences for fields as diverse as mantle flow, oceanic circulation and long-term climate change. © 2016 Macmillan Publishers Limited. |
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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/105989
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| 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: | Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Madingley Rise, Madingley Road, Cambridge, United Kingdom
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| Recommended Citation: | |
Hoggard M.J.,White N.,Al-Attar D.. Global dynamic topography observations reveal limited influence of large-scale mantle flow[J]. Nature Geoscience,2016-01-01,9(6)
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