Section Two - Coasts Flashcards
What’s a destructive wave?
A wave that carries out erosion all processes.
Name 4 processes of erosion.
Hydraulic action
Corrasion
Corrosion
Attrition
Features of destructive wave?
High frequency (10-14 waves per min)
High and steep
Backwash is more powerful than swash.
2 factors that size and power of destructive waves?
Wind
Fetch (distance of water over which the wind has blown)
Explain cliff retreat.
Erosion at base Unstable rock and wave cut notch Collapsed material Material cleared Cliff retreats
What does less resistant rock form?
Bays
What does resistant rock form?
Headlands e.g The Foreland in Swanage Bay in Dorset.
Explain how headlands become stumps.
Waves expose cracks Form caves Caves eroded into arch Arch becomes unstable and collapses Forms a stack Stack collapses and forms a stump
Where do coves forms?
Where there are parallel bands of hard and soft rock.
What’s a constructive wave?
A wave that deposits more material than it erodes.
Features of a constructive wave?
Low and long Low frequency (8-10 waves per min) Backwash is weaker than swash Made by weaker winds and shorter fetch.
Difference between sand and shingle beaches?
Sand:
Flat and wide small particles of sand
Shingles:
Steep narrow large particles
How’s a bar formed?
When a spit joins two headlands it makes a bar and a lagoon.
Name 4 hard engineering techniques to defend the coast.
Sea wall Rip rap Groynes Revetments Gab ions Breakwaters
Name 2 soft engineering techniques to defend the coast.
Beach replenishment
Managed retreat
