Fetch
The distance over which the wind blows across the sea generating waves. A longer fetch can result in longer waves which are more powerful
Swash
The movement of water up the beach after a wave breaks. It carries sediment & deposits material
Backwash
The water that flows back down the beach towards the sea, often pulling sediments with it
Wave types
Destructive and constructive
Destructive waves
They break down (destroy) the beach with erosion from strong backwash (weak swash and a strong backwash) they also have a higher hight
Constructive waves
Build up (construct) the beach with deposition from the strong swash (strong swash and a weak backwash) they have a lower height
Cliffs
Sea cliffs form through erosion by destructive waves. Hydraulic action occurs when waves crash against the cliff, compressing air and water into cracks, weakening the rock. Abrasion happens when the rocks + pebbles are carried by the waves wear down the cliff face. This erodes the base, creating a wave-cut notch. Overtime the cliff retreats as the overhang rock collapses, leaving a wave-cut platform at the base. Example the cliffs of Moher, co. Clare
Feature of coastal deposition - beach
A beach forms between the low water mark and the high water mark through the deposition of material like sand, shingles and pebbles. They are formed by constructive waves, when material is transported, moved and deposited along the coast by longshore drift. When waves lose energy, especially in sheltered bays, they deposit material, gradually building up the beach. Storm beaches form when powerful waves with strong swath through pebbles and boulders high up the shore, creating a steep ridge above the normal high tide line. E.g. sandy mount beach, Co.Dublin
