Wave Facts

  • Waves in the sea are formed when wind blows across the sea and whips the surface into ripples.
  • Water particles are dragged a short way by the friction between air and water, which is known as wind stress.
  • If the wind continues to blow long and strong enough in the same direction, moving particles may build up into a ridge of water. At first this is a ripple, then a wave.
  • Waves seem to move but the water in them stays in the same place, rolling around like rollers on a conveyor belt.
  • The size of a wave depends on the strength of the wind and how far it blows over the water (the fetch). If the fetch is short, the waves may simply be a chaotic, choppy ‘sea’. If the fetch is long, they may develop into a series of rolling waves called a swell.
  • One in 300,000 waves is four times bigger than the rest.
  • The biggest waves occur south of South Africa.
  • When waves move into shallow water, the rolling of the water is impeded by the sea-bed. The water piles up, then spills over in a breaker.
  • A wave over 40 m high was recorded by the USS Ramapo in the Pacific in 1933.