mean sea level

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mean sea level

n.
The average level of the ocean's surface, calculated as the arithmetical mean of hourly tide levels taken over an extended period and used as the standard for determining terrestrial and atmospheric elevations and ocean depths.

mean sea level

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

mean sea level

The average height of the surface of the sea for all stages of the tide; used as a reference for elevations. Also called MSL.
References in periodicals archive ?
Rising mean sea levels are already magnifying the frequency and severity of extreme sea levels, and experts predict that by the end of the century, coastal flooding may be among the costliest impacts of climate change in some regions.
5 degree temperature increase will drive the global mean sea level up by 19 inches (48 centimeters, 90 percent credible interval of 28--82 cm), while a 2.
We've had 3mm and, given the margin for error, that may mean sea levels have dropped.
OS geodetic consultant Mark Greaves said: "If mean sea levels continue to rise, then the heights of hills would drop by the same amount and some hills would cease to be mountains.
The Ordnance Survey (OS) uses mean sea level as the starting point for measuring the absolute height of mountains and rising seas have put several UK peaks at risk.
Rising sea levels are a continuing cause of concern in many parts of the world, and the most recent IPCC assessment report predicted that global mean sea levels will continue to rise at a rate that is very likely to exceed the rate of the past four decades.
Mean sea levels are expected to rise, wave climates are likely to alter ; and the frequency and intensity of storms are projected to change.
Global mean sea levels increased by about 3mm per year.
Thus, the time series representing annual mean sea levels show quite different but still increasing tendencies at six selected tide gauges, and yet decreasing trends on the northwestern coast at Ristna and Paldiski (Fig.
The correlations in case of maximum sea levels are somewhat higher than for mean sea levels.
The mean sea levels have risen along the eastern coasts of Japan and the Philippines but they have fallen along the western coasts of Japan and the Philippines, the eastern coast of China and the southern coast of Indochina Peninsula.
Forward modelling predicts that sea levels will continue to rise during the 21st Century, with a probable estimate that global mean sea levels will be around 50cm higher in 2100.