Before revision: U.S. Vanguard 1 satellite data from 1958 indicates that the North Pole's sea level is raised about with the bulge of the Southern Hemispherebeing slightly increased .
After revision: U.S. Vanguard 1 satellite data from 1958 indicates that the North Pole's sea level is raised about with higher gravitational attraction exhibited by the Southern Hemisphere, possibly due to its underlying composition .