iv. Landforms Made By Waves And Currents
Most of the changes along the coasts are accomplished by waves. When waves break, the water is thrown with great force onto the shore, and simultaneously, there is a great churning of sediments on the sea bottom.
High Rocky Coasts – Along these coasts, the river appears to have been drowned with a highly irregular coastline. Shores do not show any depositional landforms initially. Erosion features dominate.
Low Sedimentary Coasts – Along these coasts the rivers appear to extend their length by building coastal plains and details. Depositional features dominate.
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Erosional landforms |
Depositional landforms |
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Cliffs, Terraces, Caves, and Stacks – Cliffs are common on the high rocky coasts. At the foot of such cliffs, there may be flat or gently sloping platforms covered by rock debris derived from the sea cliff behind. Such platforms occurring at an elevation above the average height of waves is called wave-cut terrace. Sometimes, waves create hollows and these hollows get widened and deepened to form Sea Caves. Sea stacks are nothing but the isolated standing rocks in the sea which were once a part of the cliff. |
Bar, Barrier, and spit – A ridge of sand and shingle formed in the sea in the off-shore zone (from the position of low tide waterline to seaward) lying approximately parallel to the coast is called an off-shore bar. An off-shore bar that is exposed due to the further addition of sand is termed a barrier bar. Sometimes such barrier bars get keyed up to one end of the bay when they are called spits. A lagoon is formed when barrier bars and spits form at the mouth of a bay and block it. Others – Dunes, Beaches, etc. |