Sea Level
Mean sea level (MSL) is a measure of the average height of the ocean's surface (such as the halfway point between the mean high tide and the mean low tide); used as a standard in reckoning land elevation. MSL also plays an important role in aviation, where standard sea level pressure is used as the measurement datum of altitude at flight levels.
Read more about Sea Level: Measurement, Difficulties in Utilization, Sea Level and Dry Land, Recent Changes, Aviation
Famous quotes containing the words sea and/or level:
“People can no more be judged by their looks than the sea can be measured in bushels.”
—Chinese proverb.
“It is only for a little while, only occasionally, methinks, that we want a garden. Surely a good man need not be at the labor to level a hill for the sake of a prospect, or raise fruits and flowers, and construct floating islands, for the sake of a paradise. He enjoys better prospects than lie behind any hill. Where an angel travels it will be paradise all the way, but where Satan travels it will be burning marl and cinders.”
—Henry David Thoreau (1817–1862)