FLATTENING INTERNAL STRESS AND EARTHQUAKE
Yang Xuexiang Changchun College of Geology, 130026
The actual flattening of Earth ellipsoid is 1/298.25, which was measured by man- made satelites. It is bigger then the flattening 1/299.8 which was calculated with thcory of internal force field. It has proved that there is a few stress difference in the earth. The earth deformation which results from change of flattening and the deformation because of crustal isostasy in glacial period have almost same value by calculation. Ice age, therefore, is a cause of change of earth ellipticity at least. Crustal isostasy not only can lead to vertical crustal motion, but can generate horizontal motion. Consequently, is also is one of force source to drive ocean floor spreading and drift of continents.