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coast deposition
Question | Answer |
---|---|
what is a sandspit | a long narrow ridge of sand that extends fromm the coast out to sea |
how are they formed | they form in areas where there is a sudden change in the shape in the coastline |
why are they formed | the change in shape disrupts the process of longshore drift causing sediment to build up and deposit in a single area |
continued deposition causes the spit to grow across the bay until it reaches an area where currents and tides remove more sediment than longshore drift deposits | |
how are the sandspits stabilised | marram grass binds the sediment together. Constructive waves deposit sand on the sandspit also |
what is a tombolo | as a result of wave refraction and a change in wind direction the tip of the sandspit bends inwards and joins an island called a tombolo |
what is a baymouth bar | when a spit extends across the mouth of a bay , which can eventually block off the bay forming a lagoon |
what is a salt marsh | a dried up lagoon eg. our lady's island co. wexford |