Waves are circular movements in water.
These are caused by the friction between the wind and water. Waves can vary in size depending on the wind speed and fetch. Waves increase in size when strong winds blow over a very large fetch. Wind strength and duration effect the wave size. Waves can be described according to wave-height and wave-length.
In shallow water, the circular movement of a wave is broken when it meets the seabed. The wave height increases rapidly and causes the wave to topple over causing surf. The surf is what we normally see on our coasts when water moves up (swash) and down (backwash) the shore.
Coastlines are not always straight, like from Zonqor Point up to Kalkara.
Some bays like Ghajn Tuffieha and Gnejna Bay are divided by a headland which in this example is known as il-Qarraba. Waves moving towards such areas are slowed down and change direction by a process known as wave refraction.
Waves change the shape of the coastline by processes of erosion, transportation, and deposition.
