浅论弹性地球的自由振荡和简正模  

On the Free Oscillation and normal mode of the Elastic Earth

作　　者：戈天浩 周新 Ge Tianhao;Zhou Xin(Institute of Disaster Prevention,Langfang,China;National Institute of Natural Hazards,Beijing,China)

机构地区：[1]防灾科技学院,河北廊坊 [2]应急管理部国家自然灾害防治研究院,北京

出　　处：《科学技术创新》2023年第12期225-228,共4页Scientific and Technological Innovation

摘　　要：简正模法是一种重要理论地震图计算方法。本研究回顾了无自转、无重力、完全弹性、各向同性地球模型下基于波动方程计算理论地震图半解析解方法。分别利用二分法和斯图姆定理搜索了40 mHz、4000阶的环型和球型简正模,计算给出了它们在频率-阶数域的分布。阐述了地球自由振荡的基音与泛音及其物理意义,给出了环型振荡的基音和泛音特征。利用简正模分布解释了ScSSH振相。Normal mode method is an important theoretical seismogram calculation method.This research reviews the semi analytical solution method of seismogram based on the theory of computation of wave equation under the non-rotation,non-gravity,fully elastic,isotropic earth model.By using dichotomy and Sturm's theorem,the ring and spherical normal mode of 40 mHz and 4000 order are searched,and their distributions in the frequency order domain are calculated.Expounded the fundamental and overtones of the Earth's free oscillation and their physical significance,and provided the fundamental and overtone characteristics of the annular oscillation.The normal mode distribution is used to explain the ScSSH phase.

关 键 词：地球自由振荡 简正模 振荡特征 斯图姆定理 

分 类 号：P315[天文地球—地震学]