Coastal Deposition- slides

• Marine Deposition


  Deposition that takes place in the marine environment
• Processes of Marine Deposition

  1. When the waves have low energy

  2. Where there is a lot of material due to rapid coastal erosion

  3. When there is a reduction of energy due to a decrease in velocity

  4. Where there is reduction of energy due to a decrease in volume of water
• Situations when deposition takes place

  • When sand and shingle build up faster than they can be removed
  • When waves slow down after they have broken
  • When the water stops at the top of a swash before backwash begins
  • When water percolates into the beach material as backwash takes it back down the beach
• Aeolian (wind) deposition


  Deposition caused by the wind
• Processes of aeolian (wind) deposition

  1. Prevailing winds play an important role

  2. During the day winds come from the sea due to small pressure differentials due to the land being warmer and the sea being colder

  3. When there is a large tidal range large amounts of sand will be exposed and can be entrained (picked up) by the wind

  4. Once entrained, sand is carried close to the ground for short distances
• Ways sand is transported by the wind in coasts

  • Surface creep - wind rolls or slides grains of sand along surface
  • Saltation - when wind is strong enough to pick up sand up to 1m for for distances of 20 to 30 m