WAVE EROSION

WAVE EROSION Waves are formed by wind blowing across the surface of the sea. The stronger the wind, the more powerful the waves. The more power a wave has, the greater the amount of erosion it can cause.

WAVES IN THE CARIBBEAN In the Caribbean the prevailing winds are from the northeast. These are commonly called trade winds. The east facing coasts on islands in the eastern Caribbean are therefore exposed to high energy constructive waves. The west facing coasts tend to have much lower energy waves , as they are sheltered from the strong winds When these powerful waves ( high energy constructive waves) crash against headlands they are capable of carrying a great deal of erosion. They also drive sediment onshore to form extensive beaches.

TYPES OF WAVES There are two types of waves : Constructive Destructive Constructive waves -when waves break at a rate of ten or less a minute . These have spilling breakers. Destructive waves when waves break at a rate of ten to fifteen waves per minute. These waves removes pebbles and sand from a coast. These have plunging breakers For constructive waves, each breaking wave is able to run its course without interference from the wave behind it. For destructive waves, when waves break more frequently the backwash of a wave runs into the swash of the wave behind

WAVE MOVEMENT When the surf runs up the beach, it is called the SWASH. The swash takes sand particles and even small stones up the beach with it. The water that flows back towards the sea is called the BACKWASH. This drags sediment from the beach back into the water. Constructive waves swash carries more material than the backwash Destructive waves backwash drags more material down the beach than the swash. These erode the beach.

WAVES AS AGENTS OF EROSION Wave erode the coastline in four different ways : Hydraulic Action –the force of the waves crashing into the cliffs. Air trapped inside cracks in the cliff is compressed and blows the rock apart. Abrasion- stones and pebbles are picked up by the waves and smashed against the base of the cliff. Corrosion – some rocks such as chalk and limestone are slowly dissolved by sea water Attrition- stones and pebbles collide, knocking pieces off each other. Eventually they become particles of sand.