The force of the waves pushes air into cracks in the rock

The compressed air exerts enormous pressure at the tip of the crack. As the water falls back the air pressure is released and rock is pulled out from the crack further enlarging the hole.

What is this type of erosion called?

What features does coastal erosion What features does coastal erosion cause?cause?

1) HEADLANDS AND BAYS1) HEADLANDS AND BAYS

Headlands and baysHeadlands and bays

Headlands and baysHeadlands and bays

Why have the bays been eroded more than the headlands?Why have the bays been eroded more than the headlands?Why are headlands now more vulnerable to erosion than bays?Why are headlands now more vulnerable to erosion than bays?How do headlands protect bays from erosion?How do headlands protect bays from erosion?

Bay and HeadlandBay and Headland

Headlands and BaysHeadlands and Bays

Headlands and Bays form along coasts which have alternating bands of hard and soft rock. The geology of the coast is the most important factor controlling the shape of the coast.

Headland = where high land projects out into the sea, usually with steep cliffs.

Bay = low land, between the headlands, where the coast has retreated. Usually has a beach.

Arches, stacks and stumpsArches, stacks and stumps

Development of a Headland Development of a Headland 11

Development of a Headland Development of a Headland 22

Development of a Headland Development of a Headland 33

Formation of Arches, Stacks and Formation of Arches, Stacks and StumpsStumps Exposed lines of weakness in ______ allow

Hydraulic Action to form _____small along the base of the cliff. Over time the cave will continue to grow through _______ ______ and meet another cave on the other side of the headland forming a small ______. ______ will continue and undercut the base of the arch until it eventually falls due to lack of support and _______. This leaves behind a stack which will eventually collapse due to ___________and gravity to leave a _____.

erosion stump undercutting gravitycaves Hydraulic Action arch cliffs

Cliffs and wave Cliffs and wave cut platformscut platforms

Wave cut platform Wave cut platform formed between formed between the high and low the high and low tides as the waves tides as the waves only attack the only attack the cliff and pass over cliff and pass over the platform the platform

TRANSPORTATIONTRANSPORTATION

Long shore driftLong shore drift

• Copy the diagram down into your booklets into the middle section the A3 page.

TRANSPORTATION TRANSPORTATION Long Shore Drift (LSD)Long Shore Drift (LSD)

• Waves approach the _____ at an angle due to the direction of the ____. The ______ carry material up the beach at the same angle (due to the wind) and then down at 90º to the beach (due to the pull of______). This means ______ is carried along the beach in a zig zag pattern.

waves wind material coast gravity