WHAT IS SEA LEVEl???????

Answer 1

Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface. Defining the reference level , however, involves complex measurement, and accurately determining MSL can prove difficult.

Mean Sea Level as used by military Flight Surgeons and Aerospace Units: Using pressure to measure altitude results in two other types of altitude. True or MSL (mean sea level) is the next best measurement to absolute - and in some ways better. MSL tells you how far you are above an imaginary line at sea level. If you then know the elevation of terrain, the next step is to determine how far you are above ground. It also tells you how thin the air is, which determines your physiological response to that altitude. True Altitude (MSL) has been adjusted for local high or low pressure conditions. FL or Flight Level is another related term that is measured in hundreds of feet. At 18,000 feet, the flight level is one-eight-zero.

Answer 2

Sea level is an elevation on the earth taken at a point where the atmospheric pressure is 14.7 pounds per square inch at 20 degrees celcius.The pressure at sea level is called one atmosphere.
However the atmoshpheric pressure at sea level depends on the Gravity force which is a function of the curvature of the sea.(the sea curves around the globe)

Answer 3

SEA LEVEL
- the height of the surface of the sea midway between the average high and low tides
http://whyfiles.larc.nasa.gov/text/kids/Problem_Board/problems/habitat/glossary.html

- The ocean surface.
http://www.ed.gov/pubs/parents/Geography/glossary.html

- the imaginary line from which sea depth and land elevation are measured.
http://www.flowmeterdirectory.com/meteorology_terms.html

- The height of the sea at a given time measured relative to some datum, such as mean sea level
http://ioc3.unesco.org/itic/contents.php?id=23

- level of the ocean's surface (especially that halfway between mean high and low tide); used as a standard in reckoning land elevation or sea depth
http://wordnet.princeton.edu/perl/webwn?s=sea%20level


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http://www.google.com/search?hl=en&q=define%3A+sea+level