Junior Cycle Geography CYCLONE Types of Wave Constructive Waves
These build up a beach. Material is carried in the strong swash and is deposited up the beach. The backwash is weak.
Destructive Waves
These can destroy a beach. They are very high waves. The backwash is strong and transports beach material out to sea. The swash is weak.
Tall breaker – high downward force
High wave in Low wave in proportion to length Strong swash proportion to length
Processes of Coastal Erosion 1. Hydraulic action : This is the power of water as it crashes against the coast.
2. Abrasion : Waves pick up stones and throw them against the coast. These stones abrade the coast.
3. Compressed air : Air in rocks becomes trapped by the incoming waves. The trapped air puts pressure on the rocks. When the water retreats (moves out), the air expands and the pressure drops. This repeated compression and release causes the rocks to shatter.
4. Attrition : Stones carried by the waves hit off each other. Over time they are worn down and smoothed.
5. Solution : Certain rocks, such as limestone, are dissolved by the water.
Being creative
Using the first letter of each of the processes of erosion (H, A, C, A, S), create a fun rhyme or mnemonic to help you remember them.