Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation
文献类型：期刊论文
| 作者 | Biggin, A. J.1; Piispa, E. J.2; Pesonen, L. J.3; Holme, R.1; Paterson, G. A.4; Veikkolainen, T.3; Tauxe, L.5 |
| 刊名 | NATURE
 |
| 出版日期 | 2015-10-08 |
| 卷号 | 526期号:7572页码:245-+ |
| DOI | 10.1038/nature15523 |
| 文献子类 | Article |
| 英文摘要 | The Earth's inner core grows by the freezing of liquid iron at its surface. The point in history at which this process initiated marks a step-change in the thermal evolution of the planet. Recent computational and experimental studies(1-5) have presented radically differing estimates of the thermal conductivity of the Earth's core, resulting in estimates of the timing of inner-core nucleation ranging from less than half a billion to nearly two billion years ago. Recent inner-core nucleation (high thermal conductivity) requires high outer-core temperatures in the early Earth that complicate models of thermal evolution. The nucleation of the core leads to a different convective regime(6) and potentially different magnetic field structures that produce an observable signal in the palaeomagnetic record and allow the date of inner-core nucleation to be estimated directly. Previous studies searching for this signature have been hampered by the paucity of palaeomagnetic intensity measurements, by the lack of an effective means of assessing their reliability, and by shorter-timescale geo-magnetic variations. Here we examine results from an expanded Precambrian database of palaeomagnetic intensity measurements(7) selected using a new set of reliability criteria(8). Our analysis provides intensity-based support for the dominant dipolarity of the time-averaged Precambrian field, a crucial requirement for palaeomagnetic reconstructions of continents. We also present firm evidence for the existence of very long-term variations in geomagnetic strength. The most prominent and robust transition in the record is an increase in both average field strength and variability that is observed to occur between a billion and 1.5 billion years ago. This observation is most readily explained by the nucleation of the inner core occurring during this interval(9); the timing would tend to favour a modest value of core thermal conductivity and supports a simple thermal evolution model for the Earth. |
| WOS关键词 | GEOMAGNETIC-FIELD ; EARTHS CORE ; PALEOINTENSITY EXPERIMENTS ; TRANSPORT-PROPERTIES ; DIPOLE-MOMENT ; IRON ; CONDUCTIVITY ; EVOLUTION ; GEODYNAMO ; TIME |
| WOS研究方向 | Science & Technology - Other Topics |
| 语种 | 英语 |
| WOS记录号 | WOS:000362399000045 |
| 资助机构 | European Research Council (ERC)(267631) ; European Research Council (ERC)(267631) ; Research Council of Norway through its Centres of Excellence funding scheme(CEED 223272) ; Research Council of Norway through its Centres of Excellence funding scheme(CEED 223272) ; NERC standard grant(NE/H021043/1) ; NERC standard grant(NE/H021043/1) ; NSFC(41374072) ; NSFC(41374072) ; NSF(EAR 1345003) ; NSF(EAR 1345003) ; European Research Council (ERC)(267631) ; European Research Council (ERC)(267631) ; Research Council of Norway through its Centres of Excellence funding scheme(CEED 223272) ; Research Council of Norway through its Centres of Excellence funding scheme(CEED 223272) ; NERC standard grant(NE/H021043/1) ; NERC standard grant(NE/H021043/1) ; NSFC(41374072) ; NSFC(41374072) ; NSF(EAR 1345003) ; NSF(EAR 1345003) |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/62198]  |
| 专题 | 地质与地球物理研究所_中国科学院地球与行星物理重点实验室 |
| 作者单位 | 1.Univ Liverpool, Dept Earth Ocean & Ecol Sci, Liverpool L69 7ZE, Merseyside, England 2.Michigan Technol Univ, Dept Geol & Min Engn & Sci, Houghton, MI 49931 USA 3.Univ Helsinki, Dept Phys, Div Mat Phys, FI-00014 Helsinki, Finland 4.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing 100029, Peoples R China 5.Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA |
| 推荐引用方式 GB/T 7714 | Biggin, A. J.,Piispa, E. J.,Pesonen, L. J.,et al. Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation[J]. NATURE,2015,526(7572):245-+. |
| APA | Biggin, A. J..,Piispa, E. J..,Pesonen, L. J..,Holme, R..,Paterson, G. A..,...&Tauxe, L..(2015).Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation.NATURE,526(7572),245-+. |
| MLA | Biggin, A. J.,et al."Palaeomagnetic field intensity variations suggest Mesoproterozoic inner-core nucleation".NATURE 526.7572(2015):245-+. |
入库方式： OAI收割
来源：地质与地球物理研究所
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