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?
Headlands and Bays <ul><li>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. </li></ul><ul><li>Headland = where high land projects out into the sea, usually with steep cliffs. </li></ul><ul><li>Bay = low land, between the headlands, where the coast has retreated. Usually has a beach. </li></ul>
Formation of Arches, Stacks and Stumps <ul><li>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 _____. </li></ul>erosion stump undercutting gravity caves Hydraulic Action arch cliffs
Long shore drift <ul><li>Copy the diagram down into your booklets into the middle section the A3 page. </li></ul>
TRANSPORTATION Long Shore Drift (LSD) <ul><li>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 90 º to the beach (due to the pull of______). This means ______ is carried along the beach in a zig zag pattern. </li></ul>waves wind material coast gravity