Wave types and the coastal processes of erosion, transport and deposition; the formation of erosional landforms (headlands and bays, caves, arches, stacks, wave-cut platforms) and depositional landforms (beaches, spits, bars); and a UK coastal landscape case study.

What this dot point is asking

This is OCR GCSE Geography B (J384) Component 1, Our Natural World, within Distinctive Landscapes. OCR expects you to distinguish constructive and destructive waves, apply the coastal processes of erosion, transport and deposition, explain how erosional landforms (headlands and bays, caves, arches, stacks, stumps, wave-cut platforms) and depositional landforms (beaches, spits, bars) develop in a sequence, and study one UK coastal landscape in detail as a case study. OCR sets the requirement but lets your school choose the coast, so learn yours with named landforms.

Waves and coastal processes

Waves form when wind transfers energy to the sea surface; the fetch (the distance of open water the wind blows over), wind strength and duration set the wave energy. Constructive waves are low and long with a strong swash and weak backwash, so they deposit material and build beaches. Destructive waves are tall and steep with a weak swash and strong backwash that drags sediment seawards, so they erode the coast. Storms bring destructive waves; calm spells bring constructive ones.

The erosion processes are hydraulic action (waves compress air in cracks, blasting rock apart), abrasion (waves hurl sand and pebbles at the cliff), attrition (transported rocks knock together and round off) and solution (acids dissolve chalk and limestone). Sediment is then transported along the coast by longshore drift.

Erosional landforms

A wave-cut platform forms as a cliff retreats. Destructive waves erode a wave-cut notch at the base of the cliff between the tides; the overhanging rock collapses, the cliff retreats landward, and the gently sloping rocky surface left behind, exposed at low tide, is the wave-cut platform.

Depositional landforms

Where waves lose energy, beaches form: sandy beaches are gently sloping (constructive waves), shingle beaches steeper. A spit forms where the coast changes direction; longshore drift carries sediment past the bend and deposits a ridge out into the sea, and a change in wind curls the end into a recurved hook, with a sheltered salt marsh developing behind it (Spurn Head on the Holderness coast). A bar forms when a spit grows right across a bay, trapping a lagoon behind it.

A distinctive UK coast

OCR requires one UK coastal landscape studied in depth. A common choice is the Dorset coast (the Jurassic Coast): its alternating hard and soft rocks create a discordant section with headlands and bays (Swanage Bay) and the chalk stacks of Old Harry Rocks, while a nearby concordant section gives the cove at Lulworth. Another is Holderness, the fastest-eroding coast in Europe, where soft boulder clay retreats by around 1 to 2 metres a year and longshore drift feeds Spurn Head. Learn how the geology (rock type and structure) and the processes (waves, erosion, longshore drift) together explain the scenery and the management challenge.

Try this

Q1. Explain how a wave-cut platform forms. [4 marks]

• Cue. Waves erode a notch at the cliff base, the overhang collapses, the cliff retreats, and the rocky surface left behind is the platform.

Q2. Describe how geology can make a coastal landscape distinctive. [4 marks]

• Cue. Hard and soft rock create headlands and bays; resistant rock gives dramatic cliffs and stacks; rock structure sets whether the coast is concordant or discordant.