The elevation of a
geographiclocation 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 altitudeor geopotential heightis used for points above the surface, such as an aircraftin flight or a spacecraftin orbit.
Less commonly, elevation is measured using the center of the Earth as the reference point. Due to
equatorial bulge, there is debate whether the summits of Mt. Everest or Chimborazo are at the higher elevation, as the Chimborazo summit is further from the Earth's center while the Mt. Everest summit is higher above mean sea level.
Maps and GIS
A topographical map is the main type of
mapused to depict elevation, often through use of contour lines.
Geographic Information System(GIS), digital elevation models (DEM) are commonly used to represent the surface (topography) of a place, through a raster(grid) dataset of elevations. Digital terrain models are another way to represent terrain in GIS.
To determine elevation of a place, it must be surveyed, in reference to a
ground control point.
The elevation of a
mountainusually refers to its summit. The elevation of a hill also refers to the summit. A valley's elevation is "usually" taken from the lowest point but is often taken all over the valley.
geodesyof North America
Sea Level Datum of 1929later National Geodetic Vertical Datum of 1929( NGVD 29)
North American Vertical Datum of 1988( NAVD 88)
Highest mountain peaks of North America
List of highest mountains
List of highest towns by country
* [http://www.ngs.noaa.gov/ U.S. National Geodetic Survey website]
** [http://www.ngs.noaa.gov/CORS-Proxy/Glossary/xml/NGS_Glossary.xml Geodetic Glossary @ NGS]
** [http://www.ngs.noaa.gov/cgi-bin/VERTCON/vert_con.prl NGVD 29 to NAVD 88 online elevation converter @ NGS]
* [http://www.usgs.gov/ United States Geological Survey website]
* [http://www.gsi.go.jp/ENGLISH/ Geographical Survey Institute]
* [http://www.ngdc.noaa.gov/mgg/fliers/01mgg04.html Downloadable ETOPO2 Raw Data Database (2 minute grid)]
* [http://www.ngdc.noaa.gov/mgg/fliers/93mgg01.html Downloadable ETOPO5 Raw Data Database (5 minute grid)]
* [http://www.bivouac.com/ bivouac.com Canadian Mountain Encyclopedia]
* [http://www.peakbagger.com/ peakbagger.com]
* [http://www.peaklist.org/ peaklist.org]
* [http://www.peakware.com/ peakware.com World Mountain Encyclopedia]
* [http://www.summitpost.org/ summitpost.org]
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