Waves
When the wind blows over the sea, it creates waves. Waves erode the landscape and are a vital factor in wearing away and shaping the coast. The size and energy of the wave depends on certain factors:
- the fetch – how far the wave has travelled
- the strength of the wind
- how long the wind has been blowing for
Wave types
There are two different types of waves – Waves which help build up material on the beach. They tend to have a low frequency and strong swash. and Waves which remove material from the beach. The swash is weaker than the backwash.. They can affect the coastline in different ways. When a wave reaches the shore, the water that rushes up the beach is known as the The water flowing towards a beach when a wave breaks. . The water that flows back towards the sea is known as the The movement of water down the beach.. The energy of the swash and backwash determine the type of wave.
The characteristics of a destructive wave are:
- a weak swash and strong backwash
- occurs in stormy conditions, with strong winds
- the strong backwash removes sediment from the beach
- waves that are steep and close together
- tall waves with short wave length
- they arrive quickly and have a high frequency – a lot of them come in a short period of time
The characteristics of a constructive wave are:
- a strong swash and weak backwash
- small waves, with low wave height and long wave length
- occurs in calm conditions, without much wind
- the strong swash brings sediments to build up the beach
- the backwash is not strong enough to remove the sediment
- waves that are low and further apart
