The elevation of a geographic location is its height above a fixed reference point, often the mean sea level. Elevation, or geometric height, is mainly used when referring to points on the Earth's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit. Less commonly, elevation is measured using the center of the Earth as the reference point. Due to equatorial bulge, there's debate whether the summits of Mt. Ev… (More on Elevation)