Erosion is the wearing away of rock along the coastline. Destructive waves are responsible for erosion on the coastline. There are four types of erosion:
- Hydraulic action - this is the sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes the rock to break apart.
- Abrasion - this is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.
- Attrition - this is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.
- Solution - this is when sea water dissolves certain types of rocks. In the UK, chalk and limestone cliffs are prone to this type of erosion.