Erosion by waves forms many coastal landforms over long periods of time.
Cliffs retreat as a result of erosion, weathering and mass movements.
1) Waves cause most erosion at the foot of the cliff
2) A wave-cut notch forms, which is enlarged as erosion continues, making the cliff above the notch unstable. The part of the cliff above sea level is affected by mechanical and chemical weathering proceses also.
3) This makes the cliff more unstable and it eventually collapses.
4) The collapsed material is washed away and a new wave-cut notch starts to…