What Causes The Tides In The Sea?
The periodic rise and fall of water level in the seas or oceans is known as tide. Sometimes these tides rise so high that they look like high walls moving on the surface of the sea.
Do you know how tides are caused in the sea?
These tides are formed in the sea by the force of attraction between the earth and the moon. It is fact that in universe, all the bodies attract one another by gravitational force. As the earth and the moon are also attracted by gravitational force thus the moon is pulled towards the earth and the earth towards the moon. The force of attraction between the earth and the moon is very strong; therefore it can easily break the steel rod with a diameter of 400 kms. However the solid part of the earth cannot be affected by this force of gravitation but is causes rise and fall in the sea water. The water level in the sea keeps on rising at a point for six hours and then for the next six hours the water level keeps on falling. After every 12 hours and 25 minutes the level of sea water rises. It means that in a day and a night i.e., 24 hours and 50 minutes the tides occur two times at every place in the sea. The tides are formed in on the two spots in the seas, facing the moon as well as those on the other side. After 12 hours and 25 minutes, as the moon comes to the opposite side of the earth, the 
tides are again formed on the same two spots. The formation of tides is also affected by the force of attraction between the sun and the earth but to a very small extent. The large tide is caused when the sun, moon and earth come in a straight line, because at this time the maximum force of attraction is experienced by the earth. This large tide is known as ‘spring tide’. On the full moon and the new moon days, such types of tides are experienced by the seas. Minimum force of gravitation is experienced by the earth when the sun and the moon come in a perpendicular direction. Very small tides are formed at that time. These tides are known as ‘neap tides’ and occur between the full moon and the new moon days. The tides can rise up to 15 meters. Tides bring many precious things of seas to the sea shore.
