Work of Waves
Learning objectives: …Explain the processes of erosion, deposition and transportation at the coast. …Explain how the process of erosion creates caves, arches and stacks. …Identify different types of erosion and weathering that occur on the coast.
Prediction… How may this change in 1000 years
The formation of headlands and bays
Photograph shows headland and bays at Forvie Sands Nature Reserve – NE Scotland
Hackley Bay
Cracks Become Caves Cave formation on Ballintoy coast, Ireland http://www.youtube.com/watch?v=2fS2Swi0q-U&feature=related
Caves Become Arches An arch on Lighthouse Field state beach, California
Arches Become Stacks A stack on the South Devon coast
Joint or fault in resistant rock Roof of arch becomes too heavy to be supported and collapses A stack is an isolated part of a cliff The stack us undercut and collapses to leave a stump Waves cut through headland to form an arch which is continually widened at its base Abrasion and hydraulic action of waves widens the weakness in the cliff to form a cave Chemical weathering from the waves and rain cause the rocks to be weathered Biological weathering from roots occurs at the top of the rock.
Terminology used today: New words: Headland Bay Cliff Crack Cave Arch Stack Stump Coastal retreat Words we should have also used: Erosion Weathering Hydraulic action Solution Attrition abrasion
http://www. bing. com/videos/search http://www.bing.com/videos/search?q=formation+of+a+stack+coasts&view=detail&mid=0928E2F0EE5E7E3E134D0928E2F0EE5E7E3E134D&first=0 http://www.bing.com/videos/search?q=formation+of+a+sea+stack&view=detail&mid=3560880BE2BA51435BB53560880BE2BA51435BB5&first=0