What is Elevation?
[[File:SanBernardinoMountains8000feetsign.JPG|thumb|375px|right|An elevation sign at {{convert|8000|feet}} in the [[San Bernardino Mountains]].]] When talking about [[geography]] the '''elevation''' of a certain point is how high it is compared to some reference point. Very often, the reference point is [[mean sea level]], the level of the [[ocean]] midway between high and low [[tide]] on an average day. Most land has a positive elevation, which means it is above sea level. A few [[desert]] places are below sea level, thus have negative elevation. Sometimes elevation is measured against the center of the [[earth]]. The problem there is that the [[geoid]], the shape of the earth, does not really look like a [[sphere|ball]], it is slightly squashed (an [[oblate spheroid]]). This means, that while still at mean sea level (at the equator), some points are farther away from the center of the earth than others. That way the peak of [[Chimborazo]], a [[volcano]] in [[Ecuador]] is farther away from the center of the earth than the peak of [[Mount Everest]]. Yet, Mount Everest is higher above sea level. == Related pages == * [[Altitude]] [[Category:Physical geography]] {{geo-stub}}