Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth.
Some shorelines experience two almost equal high tides and two low tides each day, called a semi-diurnal tide. Some locations experience only one high and one low tide each day, called a diurnal tide. Some locations experience two uneven tides a day, or sometimes one high and one low each day; this is called a mixed tide. The times and amplitude of the tides at a locale are influenced by the alignment of the Sun and Moon, by the pattern of tides in the deep ocean, by the amphidromic systems of the oceans, and by the shape of the coastline and near-shore bathymetry (see Timing).
Tides vary on timescales ranging from hours to years due to numerous influences. To make accurate records, tide gauges at fixed stations measure the water level over time. Gauges ignore variations caused by waves with periods shorter than minutes. These data are compared to the reference (or datum) level usually called mean sea level.
While tides are usually the largest source of short-term sea-level fluctuations, sea levels are also subject to forces such as wind and barometric pressure changes, resulting in storm surges, especially in shallow seas and near coasts.
Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field that varies in time and space is present. For example, the solid part of the Earth is affected by tides, though this is not as easily seen as the water tidal movements.
Other articles related to "tide, tides":
... tidal waves, but this name is given by their resemblance to the tide, rather than any actual link to the tide ... Other phenomena unrelated to tides but using the word tide are rip tide, storm tide, hurricane tide, and black or red tides ...
... "And the Tide Rushes In" is song from The Moody Blues 1970 album A Question of Balance ... Written by band member Ray Thomas, "And the Tide Rushes In" connotes a sense of strife in a relationship with the narrator's lover symbolized as the tide ...
... in 2009, Ingram won the first Heisman Trophy ever awarded to an Alabama Crimson Tide player, set the Crimson Tide's single-season rushing record with 1,658 yards, was recognized as a unanimous All-American ...
... The Chesapeake Tide were a former professional Indoor Football team based in Upper Marlboro, Maryland ... The Tide were the first indoor football team to be based in Maryland ... The Owner of the Tide was Martin Johnson ...
... In Japanese mythology, the tide jewels-- individually, the kanju (干珠?, lit ... "(tide-)ebbing jewel") and manju (満珠?, lit ... "(tide-)flowing jewel")-- were magical gems that the Sea God used to control the tides ...
Famous quotes containing the word tide:
“Sweet Love of youth, forgive, if I forget thee,
While the worlds tide is bearing me along;
Sterner desires and darker hopes beset me,
Hopes which obscure, but cannot do thee wrong.”
—Emily Brontë (18181848)
“Anyone with a real taste for solitude who indulges that taste encounters the dangers of any other drug-taker. The habit grows. You become an addict.... Absorbed in the visions of solitude, human beings are only interruptions. What voice can equal the voices of solitude? What sights equal the movement of a single days tide of light across the floor boards of one room? What drama be as continuously absorbing as the interior one?”
—Jessamyn West (19021984)
“The ordinary night was graced
For them by the swift tide of blood
That silently they took at flood,
And for a little time they prized
—Howard Nemerov (b. 1920)