Why Do Waves Happen?
The waves that form on the surface of the water result due to the disturbances like wind. The other causes of waves are earthquakes that disturb the sea waters or floor of the lake. If the waves are generated by wind then their height is proportional to the speed of the wind, the time taken for the wind to blow across the water and distance to which the wind blows. The distance of the wind being blown is called as fetchÃ¢â‚¬Â. Hence, waves will become larger when there is strong wind, long duration wind blow and longer fetch. The growing of waves to more heights is found to be the function of water depth. Tsunami is a condition where the waves are created by the displacement of sea floor.
There are other types of waves called standing waves. Standing waves occur due to the vibrations that go on in a steady way. When any wave hits a barrier and reflects back there is addition and subtraction of energy in the wave. In the case of a string, the forward wave and the reflected one are competing with each other and the energies are added and subtracted. The result of this is called as standing wave. These two waves will have high impact on one another at certain frequencies as the original wave has high and low amplitudes. The reflected wave will synchronize with the original one by matching the crests and troughs of the first wave. This results in the standing wave which is stronger.
The waves in the sea are formed by the gravitational pull of the moon with the gravity of the moon pulling the water up from the ocean. As the gravity of the moon is only 1/6th that of the earth it is not very strong and the water flows back due to the gravity of earth. So, the rise of water due to moon’s gravity pull and falling down of water due to earth’s gravity creates the wave.