The Lower Limit of Variation of the Earth′s Oblateness in Geological Epoch
详细信息
- 责任者：Wang Junheng (Key Laboratory of Geo-Detection ; Ministry of Education ; Beijing 100083 ; China) ; Li Xinjun
- 刊名：Chinese Journal of Geophysics
- 出版年：2013
- 卷期：56(3)
- 关键词：地球形状 ; Earth figure ; 地球演化 ; Earth evolution
- 页码：p.842-847
- 图表：illus., 2 tables, 9 refs.
- 分类号：0400
- issnNo：ISSN0001-5733
- isbnNo：CN11-2074/P
摘要
A variation in the earth′s shape is one of the basic problems of earth evolution.A variation in the earth′s oblateness can be used to understand the variation of the earth′s shape.Assuming the Earth is flexible ellipsoid,according to the theory of elastic dynamics,we derived the formula for minimum oblateness of the Earth and conclude that oblateness of the Earth is a function of the average density of the Earth ρ,the gravitational acceleration g,rotation rate ω,average radius R,elastic modulus E and Poisson′s ratio v.Apply parameters such as the radius,mass,and the change in angular velocity of the Earth,which are based on the new nebular hypothesis,into the formula to calculate the lower limit of oblateness of the Earth in different geological epoch.The oblateness of the Earth has signs of reduction in its magnitude since the formation of the Earth.