核幔边界动力学——地球自转十年尺度波动

doi:10.11867/j.issn.1001-8166.1999.06.0541

地球科学进展 ›› 1999, Vol. 14 ›› Issue (6): 541 -548. doi: 10.11867/j.issn.1001-8166.1999.06.0541

核幔边界动力学——地球自转十年尺度波动

傅容珊 ^①,李力刚 ^①,郑大伟 ^②,薛霆啸 ^①

①中国科学技术大学地球和空间科学系,安徽合肥 230026;第三世界科学院中国科学技术大学地球科学和天文学高级研究中心,安徽合肥 230026;②中国科学院上海天文台,上海 200030

收稿日期:1998-12-01 修回日期:1999-05-14 出版日期:1999-12-01
通讯作者: 傅容珊,男,1942年出生,教授,主要从事地幔对流、岩石层应力场、大陆演化以及地球各圈层耦合动力学研究。
基金资助:
国家攀登计划“现代地壳运动和地球动力学研究”(编号:97023103)资助。

DYNAMICS OF THE CORE-MANTLE BOUNDARY AND THE DECADAL FLUCTUATION IN THE EARTH’S ROTATION

FU Rongshan ^①, LI Ligang ^①, ZHENG Dawei ^②,XUE Tingxiao ^①

①University of Science and Technology of China,Hefei, 230026China,Advanced Research Center for Geoscience and Astronomy,Third World Academy of Science,Hefei230026,China;②Shanghai Astronomical Observatory,the Chinese Academy of Sciences,Shanghai 200030,China

Received:1998-12-01 Revised:1999-05-14 Online:1999-12-01 Published:1999-12-01

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总结了地球核幔边界动力学有关研究的新进展,如核幔边界的特性、核幔边界的地形起伏、核幔边界附近地幔对流格局和地球外核顶部的流场等。从地核—地幔之间的耦合出发,讨论了地球自转十年尺度的波动问题,简述了核幔之间电磁耦合、粘滞耦合和地形耦合对十年尺度波动影响的基本理论。提出在该项研究中应以综合分析为基础,开展多学科的联合、交叉研究的途径以深化对地球自转十年尺度波动机理的认识。

关键词: 地球自转变化, 十年尺度波动, 边界耦合, 核幔边界

The new advances in the researches on the core-mantle boundary (CMB) dynamics are summarized in this paper. They are the studies of the structure and characteristics of the CMB, the topography of the CMB, the patterns of the mantle convection near the CMB and the core flow at the top of the outer core. On the basis of the coupling between the core and mantle, the decadal fluctuation in the Earth' s rotation is discussed. We also introduce the basic theory of the electromagnetic coupling, the viscous coupling and the topography coupling at the core-mantle interface and their influences to the decadal fluctuation in the Earth' s rotation. At the end of this paper authors emphasize that in order to understand the nature of the decadal fluctuation in the Earth' s rotation the best way is to develop a coordinate model, which will joint different scientific areas such as the astronomy, geophysics, geodynamics, space geodecy and so on.

Key words: Core-mantle boundary, Variation of Earth' s rotation, Decadal fluctuation, Coupling of interface.

中图分类号:

P183.3

〔1〕Hide R, Horai K I. On the topograpgy of the core-mantle interface〔J〕. Phys Earth Planet Inter, 1968, 1: 305～308.
〔2〕Hide R. Interaction between the Earth' s liquid core and solid mantle〔J〕. Nature, 1969, 222: 1 055～1 056.
〔3〕安德森D L.地球的理论〔M〕.关华平等译.北京:地震出版社,1993. 480P.
〔4〕US CSEDI Coordinating Committee.〔R〕. 1993.
〔5〕Olson P,et al. Small-scale convection in the D"-layer and the roughness of the core-mantle boundary〔J〕. Eos Trans AGU,1986, 67: 1 201.
〔6〕Bloxham J, Gullins D,Jackson A. Geomagnetic secular variation〔J〕. Phil Trans Roy Astr Soc, 1989, 329: 415～502.
〔7〕Stacey F D. Physics of the Earth〔M〕. Third Edition Brook-field Press, 1993. 513P.
〔8〕拉姆贝克K.地球物理大地测量学——地球的慢形变〔M〕.黄立人等译.北京:测绘出版社,1995. 515P.
〔9〕Morelli A,Dzienonski A M. Topography of the core-mantle boundary and lateral heterogeneity of liquid core〔J〕. Nature,1983, 325: 678～683.
〔10〕Hager B H,Clayton R W,Richardsl M A,et al. Lower mantle heterogeneity, dynamic topography and the geoid〔J〕. Nature, 1985, 313: 541～545.
〔11〕Gubhins D, Richards M A. Coupling of the core dynamo and mantle: thermal or topographyic〔J〕. Geophys Res Lett,1986, 13: 1 521～1 524.
〔12〕Fu R S, Huang J H. Earth' s geoid, plate motions, seismic tomography of the mantle and CMB topography〔J〕. J Geo-mag Geoelectr, 1993,45:1 248～1 249.
〔13〕Runcorn S K. Flow in the mantle inferred from low degree harmonics of geopotential〔J〕. Geophys J R Astron Soc,1967, 14: 375～384.
〔14〕Fu R S. A numerical study of the effects of boundary conditions on mantle convectionmodels constrained to fit the low degree geoid coefficients〔J〕. Phys Earth Planet lnter, 1986,44: 257～263.
〔15〕傅容珊,陈凌,黄建华,等.全球地震层析地幔密度横向不均衡及大陆动力学〔J〕.地球物理学进展,1995, 10(3): 51～62.
〔16〕傅容珊.地幔热动力学模型〔J〕.地球科学进展, 1993,8(2):13～26.
〔17〕Bloxham J, Jackson A. Fluid flow near the surface of Earth' s outer core〔J〕. Reviews of Geophysics, 1991, 29: 97～120.
〔18〕Alfven H. On the existence of electromagnetic-hydromagnetic waves〔J〕. Arkiv Mat Astron Fys, 1942, 29B(2):7.
〔19〕Roberts P H, Scott S. On the analysis of the secular variation, 1. A hydromagnetic constraint: Theory〔J〕. J Geomag Geoelectr, 1965, 17: 137～151.
〔20〕Gubbins D, Roberts P H. Magnetohydrodynamis of the Earth' s core〔A〕.In: Jacobs J A, ed. Geomagnetism. Vol 2,〔C〕. San diego:Academic, 1987. 183.
〔21〕Bullard E C, Gellman H. Homogenous dynamo and terrestrial magnetism〔J〕. Phil Trans R Soc Lond 1954, A 247: 213～278.
〔22〕Gubbins D. Finding core motions from magnetic observations〔J〕. Phil Trans R Soc London Ser A, 1982, 306: 247～254.
〔23〕Backus G E. Kinematics of geomagnetic secular variation in a perfectly conducting core〔J〕. Phil Trans R Soc London Ser,1968, A 263: 239～266.
〔24〕Hills R G. Convection in the Earth' s Mantle and due to Viscous Shear at the Core-mantle Interface and due to Large-scale Buoyancy〔Ph D Thesis〕.Las Crucees: N M State University, 1979.
〔25〕LeMouel J L. Outer core geostrophic flow and secular variation of the Earth' s magnetic filed〔J〕. Nature, 1984, 311:734～735.
〔26〕Higgins G, Kennedy G C. The adiabatic gradient and the melting point gradient in the core of the Earth〔J〕. J Geophys Res, 1971, 76: 1 870～1 878.
〔27〕Bloxham J. Simple model of fluid flow at the core surface derived from geomagnetic field models〔J〕. Geophys J Int,1989, 99: 173～182.
〔28〕Voorhies C V. Steady flows at the tope of Earth' s core derived from geomagnetic field models〔J〕. J Geophys Res,1986, 91: 12 444～12 466.
〔29〕Gire C, Le Mouel J L. Tangentially geostrophic flow at the core-mantle boundary compatible with the observed geo-magnetic secular variation: The large-scale component of the flow〔J〕. Phys Earth Planet inter, 1990, 59: 259～287.
〔30〕Munk W H, MaCdonlad G S F. The Rotation of the Earth〔M〕. Cambridge:Cambridge Universtiy Press, 1960.
〔31〕Lambeck K. The Earth' s Variable Rotation〔M〕. London and New York: Cambridge University Press, 1980.
〔32〕Hide R. Fluctuations in the Earth' s rotation and the topography of the core-mantle interface〔J〕. Phil Trans R Soc Lond A, 1989, 328: 351～363.
〔33〕李金岭,郑大伟,傅容珊.地球自转十年尺度波动以及核幔耦合的可能机制〔J〕.地球科学进展. 1997, 12(6): 514～518.
〔34〕Voorhies C V. Coupling an inviscid core to an electrically insulating mantle〔J〕. J Geomag Geoelectr, 1991, 43: 131～156.
〔35〕Rochester M G. Geomagnetic core-mantle coupling〔J〕. J Geophys Res, 1962, 67: 4 833～4 836.
〔36〕Bullard E C. Freedman C, Gellman H,et al. The westward drift of the Earth' s magnetic field〔J〕. Phil Trans R Soc Lond, 1950, A 243: 67～92.
〔37〕Hide R. Towards a theory of irregular variations in the length of the day and core-mantle coupling〔J〕. Phil Trans R Soc London A, 1977, 284: 547～554.
〔38〕Hide R . The topographic torque on a bounding surface of a rotating gravitating fluid andthe excitation by core motions of decadal fluctuation in the Earth' s rotation〔J〕. Geophys Res Lett, 1995, 22(8): 961～964.
〔39〕Hassan M H A. Eltayeb I A. On the topography coupling at the core-mantle interface〔J〕. Phys Earth Planet Inter, 1982,28: 14～26.
〔40〕Jault D, LeMouel J L. Exchange of angular momentum between the core and the mantle〔J〕. J Geomag Geoelectr,1991, 43: 111～129.
〔41〕Song X D, Richards P G. Seismological evidence for differential rotation of the Earth' s inner core〔J〕. Nature, 1996,382: 221～224.

[1]	朱介寿. 下地幔及核幔边界结构及地球动力学[J]. 地球科学进展, 2000, 15(2): 139-142.
[2]	李金岭，郑大伟，傅容珊. 地球自转十年尺度波动与核幔耦合的可能机制[J]. 地球科学进展, 1997, 12(6): 514-518.
[3]	侯渭,谢鸿森. 关于地核和核慢边界区物质的成分及运动特征的研究进展[J]. 地球科学进展, 1996, 11(2): 204-208.

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