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Unit 5: Gradational Processes . Wave Action and Coastal Landforms . http://www.youtube.com/watch?v=ITv6gSUmTjc http://www.youtube.com/watch?v=Hw6sDulj7GA&feature=related. Wave Action.
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Unit 5: Gradational Processes Wave Action and Coastal Landforms
http://www.youtube.com/watch?v=ITv6gSUmTjc • http://www.youtube.com/watch?v=Hw6sDulj7GA&feature=related
Wave Action • Waves that hit gently sloping beaches begin their breaking motion far from shore and are called constructive or spilling wavesas they build the beach. • When waves strike steeply sloping beaches, the breaking motion does not begin until the wave is close to shore these waves are called destructive or plunging waves.
Wave Types and Movements • Waves of oscillation: characteristic wave of deep water. Wave particles move in a circular motion. • Waves of translation: powerful horizontal movement of waves responsible for most shoreline erosion • Waves of refraction: wave action on shoreline. Responsible for headland erosion.
Erosional action by waves • Corrosion: material absorbed by the salt content in water • Abrasion: sediment (sand) carried in water can wear down rock surfaces. • Attrition: rock particles striking each other and fracture. • Hydraulic Action: wind generated waves strike shoreline going into cracks of rock and widening gaps. What processes needs fast moving water?
Undercutting • Erosional action along shorelines occurs at the base of the cliff. • Rock is cracked and worn down by hydraulic action • Process called undercutting creating steep and vertical cliffs • Cliffs begin to retreat decrease stability cliff can collapse