What Causes The Ocean Tides?


5 Answers

Daisy Sarma Profile
Daisy Sarma answered
We all know the phenomenon of the tides that are seen in the oceans. The tides are nothing but the rising and falling of the ocean surface of the earth. The immediate effects of tides are the changing depths of the oceans at that instance in time, and also the generation of tidal streams, which are nothing but oscillating currents in the seas. So what causes the tides? A simple explanation could be the gravitational force that the moon exerts on the earth's surface and vice versa. Basically, the gravitational pull of an object diminishes with distance. As the object moves further away, the gravitational force it exerts decreases. It is because of this that the side of the moon that is closer to the earth's surface pulls the water of the ocean upwards, while the side that is further away pulls it back downwards, though this force is weaker than the one exerted by the one at the near side of earth. Along with this, the earth exerts its own gravitational force on the water, which is stronger than the moon's and ensures that the net force is always stronger on the downside. This is why the oceans do not fall off the earth's surface.
Chris Hickman Profile
Chris Hickman answered
The change in level of the oceans and sea is caused by the joint effect of centrifugal force and gravitational attraction between the Earth and the Moon. There is, to a lesser extent, also an effect caused by the attraction between the Sun and the Earth.
Although several heavenly bodies apply gravitational pulls on the Earth's oceans, it is the Moon and Sun which have the most influence. These two bodies cause the envelope of the oceans to become egg-shaped. With the Earth spinning within this envelope it gives the impression that the water is rising and falling on its surface. The water rises over a six-hour period and then falls over a similar time.
For the sea level to fall from high water and return to high water again, one cycle, takes 12 hours. Such a tide is known as semi-diurnal. There are places around the world, like the Pacific, where the cycle takes 24 hours and this is known as a diurnal tide.
Saadia Samad Profile
Saadia Samad answered
Everyone who has visited the she shores knows the tides. Twice each day, the water rises, twice a day it recedes.

There is an interval of about twelve hours between each high or flood type and the same interval between each low and ebb tides. Tides are caused by the gravitational pull of the moon on the earth the sun, to, has its gravitational pull, which is huge compared to the moon, but the moon is so much nearer the earth that its tide. Rising force is more then twice as great as that of the sun. The ratio is about 9:4.

Sometimes the moon and the sun pull to gather. The result is an unusual high tide. Sometimes they pull in different directions. The result is an unusual low tide. The sun can only help or hinder the tide rising effect of the moon's pull. The moons pull effects the liquid covering of the earth much more easily then the solid portions. The water on the side of the earth nearest to the moon gets heap up into a great wave.

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