- Hydraulic action: impact of water (not rocks) hitting the rocks/cliffs – exerts lots of pressure on the surface so weakens it – can also be called wave pounding
- Wave quarrying: As a wave breaks against a cliff face, it traps air in cracks – it creates a lot of pressure – when water pulls back, the air being released has an explosive effect – over time, this process greatly weakens the cliff face – storms can remove large chunks of the cliff
- Abrasion/corrasion: The sea picks up material which can wear away at the cliff face – as waves break, the sea can throw sand, shingle and boulders at the cliff which will do lots of damage
- Attrition: rocks carried in the sea can hit against each other, so it is worn down into smaller and more rounded pieces
- Solution/corrosion: Technically, this is weathering but it does contribute to coastal erosion – calcium-based rocks dissolve in the sea – the actual seawater is probably not the agent of this because the pH is stable at around 7.5-8.5 which is very slightly alkaline – therefore, it probably happens where there is slightly acidic rainwater
