Tides - History, Theories Of Tidal Action, Variables Affecting Tidal Forces, Tide Tables, Semidiurnal And Diurnal Tides
bodies
Tides are deformations in the shape of a body caused by the gravitational force of one or more other bodies. All bodies in the universe exert tidal forces on each other, although the effects are generally too small to observe. As far Earth is concerned, the most important tidal phenomena are the ocean and ground tides that occur as a result of the Moon's and the Sun's gravity.
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The side of the Earth that faces the Moon experiences a larger gravitational pull, due to the Moon's closer proximity, than other parts of the Earth. This force causes the Earth itself to bulge slightly toward the Moon. This bulge is termed an Earth tide. Since water is free to move horizontally, the oceans tend to flow over the Earth's surface and collect in a secondary bulge on top…
Physicists have derived precise mathematical expressions to describe the gravitational effects of the Moon and the Sun on the Earth. In theory, therefore, it should be possible to make precise predictions of the timing and sizes of all of ocean tides. In fact, absolutely precise predictions
Low tide at Big Pine Key, Florida. JLM Visuals. Reproduced by permission.
are not possible because a…
In most places, tides are semidiurnal (twice-daily), meaning that there are two tidal cycles (with one high tide and one low apiece) each day. In other words, during a typical day the tides reach their highest point along the shore and their lowest point twice each day. The high-water level reached during one of the high tide stages is usually higher than the other high point, and the low
High …
Any movement of ocean water caused by tidal action is known as a tidal current. In open water, tidal currents are relatively weak and tend to change direction slowly and regularly throughout the day. They form a kind of rotary pattern that sweeps around the ocean like the minute hand on a clock. Closer to land, however, tidal currents tend to change direction rather quickly, flowing toward land du…
(1) Because the Earth's comparatively rapid rotation is continually dragging the tidal bulges away from their ideal locations, the Moon-facing bulge is always slightly ahead of the Moon in the direction of its orbit. (The Moon orbits in the same sense as the Earth spins.) The gravitational pull of the bulge thus tends to accelerate the Moon slightly, which causes it to orbit slightly higher…
Engineers have long recognized that the movement of tidal currents might be an inexpensive, efficient, and environmentally safe source of power for human use. In general, the plan would be to construct a dam across the entrance of an estuary through which tidal currents flow with significant speed. Then, as tidal currents flow into and out of the estuary twice each day, they could be used to drive…
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User Comments
2 months ago
iqra shahid
hello i want o know about the history o tidal action theory......
10 months ago
hi
over 4 years ago
I would like to know why the highest tides where I live (Hawaii) only reach 2.6 feet and in other palces the tides are significantely higher and lower. I know from some research the bottom of the ocean and land formations affect this but the facts are still a little confusing.
Can you explain this better?
Mahalo,
Mike