COASTAL LANDFORMS

Erosion landforms

headlands and bays, cliffs and wave cut platforms, caves, arches and stacks

Where do headlands and bays occur

disconcordant coastlines

What is a disconcordant coastline

different types of rock, erosion happens at different rates

How are Headlands and bays formed

sea erodes soft rock to form bays, leaves harder rocks standing out as headlands

How are Cliffs and wave cut platforms formed

Sea attacks base of the cliff
Notch is formed by abrasion + hydraulic action
Notch increases in size
Cliff becomes unstable and collapses
Backwash carries eroded material leaving a wave cut platform
Process repeats and cliff continues to retreat

How are caves, arches, stacks and stumps

Cracks widened in headland by hydraulic action and abrasion

Waves continue to grind at crack and forms a cave

Cave becomes larger, breaks through headland forming an arch

Base of arch continually widens through erosion

Roof becomes too heavy, collapses leaving a stack

Stack is undercut at base till collapses, stump formed

Deposition landforms (4)

beaches, sand dunes, spits and bars

How are beaches formed

Eroded material that has been transported from elsewhere
Deposited by the sea
Constructive waves build up beach (strong swash, weak backwash)

Where do sand dunes form

long, dry sandy beaches

How are sand dunes formed

wind blows sand sediments to the back of the beach

What are the 3 type of sand dunes

grey dunes,embryo dunes, yellow dunes

Formation of grey dunes

Sand develops into soil
Vegetation grows here and dies
Adds nutrients to sand
More plants of different types

Formation of embryo dunes

Upper beach area
Sand starts accumulate around a small object

Formation of yellow dunes

Sand accumalates and dune grows
Vegetation develops on upper and back surfaces
Stabalises dune

Spits characteristics

extended stretch of sand from land jutting out into the sea

How are spits formed

Sediment carried by longshore drift
Change in the shape of the coastline
Deposition occurs
Long ridge of material is deposited