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Types of Coastline. Submergence and emergence changes coastlines. Pocket beaches. Emergent coast. Uplifted land surface Coastal landforms are found above present sea level. a wave-cut platform when elevated - uplifted marine terrace. Submergent coast. Rise in sea level Submergent coast
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Types of Coastline Submergence and emergence changes coastlines Pocket beaches
Emergent coast • Uplifted land surface • Coastal landforms are found above present sea level a wave-cut platform when elevated - uplifted marineterrace
Submergent coast • Rise in sea level • Submergent coast • Landforms under water • A ria coastline is an example of submergence
Submergence Shorlines • Ria coast - shorline valleys eroded by rivers are submerged • has many offshore islands • exposure to waves erodes islands and headlands • Fiord coast - shoreline valleys created by glaciers are submerged • valleys are deep and straight • because of the depth, there are few beaches
Barrier Island Coasts • Occur on low lying coasts with gentle gradients • BARRIER ISLANDS - low ridges of sand built by waves • behind the islands are lagoons • shallow water with tidal deposits • TIDAL INLETS - gaps between the islands
Delta and Volcano Coasts • DELTA - deposit by rivers entering the sea • Water slows down and spreads out as it enters • Channel divides and subdivides to create DISTRIBUTARIES • Volcano coasts develop in volcanic deposits • Low cliffs form in fresh lava
Coral reefs • Corals build up calcium deposits to produce reefs • To grow, corals need: • Clear, warm, shallow water • Wave action Corbis Digital Stock
Coral reefs • Fringing reef - directly attached to an island or coast • Barrier reef - lagoon between coast and reef • Atoll reef - circular reef surrounding a lagoon (no land in centre)