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Article: Sea Level
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- Water:Science and Issues
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CopyrightCOPYRIGHT 2003 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Sea Level
Sea level is defined as the height of the sea surface above an equipotential surface, called the geoid. The geoid is where the sea surface would come to rest in the absence of tides, water density variations, currents, and atmospheric effects. If the oceans did not move and there were no tides or wind, the sea surface and geoid would be the same surface.
Mean Sea Level
Because of tidal and wind-driven changes, sea level is constantly fluctuating. Therefore, it is important to calculate the mean sea level, which is the average sea level at a given location over several years.
Global changes in the mean sea level, which are due to other factors than those discussed above, are ...