mean sea level

American  

[meen see lev-uhl] / ˈmin ˈsi ˈlɛv əl /

noun

1. Oceanography. the average height of the ocean's surface, as measured frequently and during all fluctuations of tides and atmospheric conditions over an extended time, usually a number of years.

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mean sea level British  

noun

1. (in the UK) the sea level used by the Ordnance Survey as a datum level, determined at Newlyn in Cornwall See sea level

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mean sea level Scientific  

1. See under sea level

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Example Sentences

Last year, the global mean sea level was around 11 centimetres higher than when satellite altimetry records began in 1993.

From Barron's • Mar. 23, 2026

In Redondo Beach, for instance, a near-shore tsunami could bring waves of up to 11 feet above mean sea level, compared to 9 feet possible coming from a distant earthquake.

From Los Angeles Times • Jun. 8, 2025

The fjords plunge 4,856 feet and 2,034 feet, respectively, below the global mean sea level.

From Scientific American • Nov. 3, 2023

The last of the helicopter’s data transmissions sent every three minutes indicated it was traveling in a northwesterly direction at an altitude of 144 feet above mean sea level at 107 mph, the report said.

From Washington Times • Aug. 9, 2023

Winds at 2,000 feet above mean sea level are shown.

From A Quantitative Study of the Nocturnal Migration of Birds. Vol.3 No.2 by George H. Lowery.

Related Words

• water level