地球液核的动力学效应研究进展

doi:10.11867/j.issn.1001-8166.2002.05.0664

地球科学进展 ›› 2002, Vol. 17 ›› Issue (5): 664 -669. doi: 10.11867/j.issn.1001-8166.2002.05.0664

地球液核的动力学效应研究进展

徐建桥,孙和平

中国科学院测量与地球物理研究所动力大地测量学重点开放实验室，湖北武汉 430077

收稿日期:2001-11-29 修回日期:2002-03-22 出版日期:2002-12-20
通讯作者: 徐建桥(1965-)，男，湖北红安人，副研究员，现主要从事固体地球潮汐理论，观测资料分析、结果理论解释及其在地球动力学研究中的应用等方面的研究工作.E-mail: xujq@asch.whigg.ac.cn E-mail:xujq@asch.whigg.ac.cn
基金资助:
国家自然科学基金项目“地球液核动力学效应的研究和检测”（编号：40174022）；“全球地球动力学的重力效应综合研究”（编号：49925411）；中国科学院知识创新工程重要方向项目“中国大陆形变场和重力场时空变化及动力学机制研究”(编号：KZCX2-106)资助.

ADVANCES IN THE STUDY ON THE EFFECTS OF THE EARTH'S FLUID OUTER CORE

XU Jian-qiao, SUN He-ping

Key Laboratory of Dynamic Geodesy, Institute of Geodesy and Geophysics, CAS, Wuhan 430077,China

Received:2001-11-29 Revised:2002-03-22 Online:2002-12-20 Published:2002-10-01

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简要介绍了液核动力学研究的方法及液核动力学效应检测的进展和研究结果，着重介绍了超导重力仪在液核动力学研究中的作用。基于初始参考地球模型（PREM），采用球对称、非自转、完全弹性和各向同性地球的弹性引力形变理论研究了液核动力学扰动导致的地球固体部分的形变和重力位扰动。根据重力潮汐观测中的近周日共振特征，利用国际超导重力仪观测资料研究了地球的自由核章动（FCN），精密确定了有关的共振参数，其中FCN的本征周期为429.0（424.3，4 433.7）恒星日，品质因子为 9543（6405，18714），复共振强度为（－6.10±0.20，－0.01±0.20）×10^－4°/h。最近，我们还估计了全球地球动力学观测网中全球分布的14台超导重力仪21个长期、连续重力观测序列的"积谱密度"以检测固体内核的平动振荡运动。

关键词: 液核动力学, 超导重力仪, 自由核章动, 固体内核的平动振荡

The techniques to study the global geodynamics of the Earth's fluid outer core, the advances in the detection of its dynamical effects and some results are briefly reviewed. The roles of the superconducting gravimeters on the study on the fluid core dynamics are specially emphasized on. Based on the preliminary reference Earth's model, the elasto-gravitational deformation theory of a spherical, non-rotating, perfectly elastic and isotropic (SNREI) Earth is employed to study the deformation of the Earth's solid parts (including the mantle and the solid inner core) caused by the perturbation on the core-mantle and inner core boundaries due to the dynamical effects of the fluid outer core. According to the nearly diurnal resonance on the tidal gravity observations, the Earth's free core nutation is investigated by stacking the gravity data recorded with international six super- conducting gravimeters. The corresponding resonance parameters are accurately determined as 429.0 (424.3, 433.7) sidereal days for the egeinperiod, 9 543 (6 405, 18 714) for the quality factors, and (-6.10±0.20, -0.01±0.02) ×10^-4 °/h for the complex resonance strength. Recently, the product spectral density of 21 long-term and high-quality gravity data sequences, obtained with 14 superconducting gravimeters globally distributed at the Global Geodynamics Project observatory network, are estimated in order to search for the translational oscillations of the solid inner core.

Key words: Fluid core dynamics, Superconducting gravimeters, Free core nutation, Translational oscillations of the solid inner core.

中图分类号:

P312

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