液核动力学扰动引起的地球形变  

EARTHS DEFORMATION DUE TO THE DYNAMICAL PERTURBATIONS OF THE FLUID OUTER CORE

作　　者：徐建桥[1] 孙和平 

机构地区：[1]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,中国武汉430077

出　　处：《地震学报》2002年第4期397-406,共10页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(40174022;49925411);中国科学院项目(KZ9S2-J1-411;KZ952-J1-411)联合资助.

摘　　要：讨论了地球固体部分对液核动力学效应引发的核幔边界和内核边界上压力和引力扰动的形变响应.采用弹性-引力形变理论描述地幔和内核的形变,给出了内部负荷Love数的一般表达式.以初始参考地球模型为例,分别计算了在地球表面、核幔边界和内核边界上的内部负荷Love数.探讨了液核边界上压力和引力扰动导致的地球形变场的空间和频率分布特征.本文的结果可以为中短周期液核动力学理论模拟提供必要的边界条件.The elasto-gravitational deformation response of the Earths solid parts to the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB), due to the dynamical behaviors of the fluid outer core (FOC), is discussed. The internal load Love numbers, which are formulized in a general form in this study, are employed to describe the Earths deformation. The Preliminary reference Earth model (PREM) (Dziewonski, Anderson, 1981) is used as an example to calculate the internal load Love numbers on the Earths surface, CMB and ICB, respectively. The characteristics of the Earths deformation variation with the depth and the perturbation periods on the boundaries of the FOC are investigated also. The numerical results indicate that the internal load Love numbers decrease quickly with the increasing degree of the spherical harmonics of the displacement and depend strongly on the perturbation frequencies, especially on the high frequencies. The results, obtained in this work, can be used to construct the boundary conditions for the core dynamics of the long-period oscillations of the Earths fluid outer core.

关 键 词：液核动力学效应 液核边界 内部负荷Love数 地球 形变场 边界条件 地震 核幔边界 

分 类 号：P542.5[天文地球—构造地质学] P315.725[天文地球—地质学]