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?
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 _____.
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.