地震激发的地球自由振荡研究综述

A review of the Earth's free oscillations excited by Earthquakes

地球自由振荡的研究已成为探查地球内部结构的重要手段之一.影响地球自由振荡的因素有很多,如地球物理学结构横向不均匀性及径向不均匀性、地球自转、地球椭率、地球内部各向异性、非弹性性以及震源机制性质,还有地球外界如引潮力等.本文详细介绍和总结了近几十年来关于地球自由振荡理论研究、实验及观测资料方面的研究,重点是数值模拟方法方面的研究工作.通过观测和理论分析对比,以数值实验的方式推测地球内部更详细的结构分布,如地球内部密度分布以及波速度等特性;并从弹性波理论出发结合高性能并行计算对全球自由振荡过程进行数值模拟研究.

The research of the Earth＇s free oscillations has become one of the major means to study the Earth＇s internal structure. There are many factors concerning with the Earth＇s free oscillations, such as the Earth＇s lateral heterogeneity and radial heterogeneity, selbrotation, ellipticity, anisotropy, anelasticity and focal mechanism, together with other factors such as tidal and atmosphere pressure effects. In this paper, we make a brief review of the researches and developments on the Earth＇s free oscillation theories and observation results. We focus on the analytical and numerical methods to conduct the detailed research work on these phenomena. Through comparing the experiment and observation results with the theoretical or numerical simulation results, we will be able to image more detailed Earth＇ s internal structure, such as material density distribution and elastic wave speeds. The combination of the elastic wave theory and high-performance parallel computational technology for the research of the Earth＇s free oscillations is also discussed briefly.