Some sort of force or energy is needed to start a wave, and it is the wind that provides this energy in the water. Wind blows the surface layers of the sea, gradually a rolling movement of waves. As these waves near the coast, the sea-bed interrupts their rolling movement and they mount up and break onto the beach. The water inside a wave moves round and round in a circle. Near the shore, the circular shape of the wave is changed and it becomes squashed. The top of the wave becomes unstable, so when it hits the beach, it topples and spills over. On beaches with a shallow slope the waves pile up to a great height before breaking, causing surf.
|
Fact File: For centuries sailors have been in terror of being sucked into a whirlpool that would swallow them and their ships. Whirlpools happen when opposing currents meet. |
Picture Credit : Google