Depositional Landforms

Formed by low energy waves, sand and shingle acummilating faster than removed and an abundant supply of material
Beaches
1. Sand - gentle gradient (5 degrees) as small particle size doesn't allow percolation so most of the swash is backwashed
2. Ridges - when the material is carried down the beach it creates ridges
  1. Runnels - created in the dips between ridges where water acummilates
3. Storm Beach
  1. Created by strong swash at spring high tide at the back of the beach
  2. A ridge composed by the biggest boulders thrown by the largest waves
4. Berms - a series of ridges marking the successively lower high rides as the cycle goes from spring to neap
5. Shingle - steeper gradient (10-20 degrees) as water rapidly percolates though shingle as it has large gaps between sediment
  1. This means the is less backwash therefore little sediment is carried back down the beach
6. Cusps - semicircular shaped depressions which form when waves break directly onto the beach
7. Ripples - developed on the sand by wave action or tidal currents
Spits
1. Long narrow piece of land joined to the mainland which projects out to sea or across a river estuary
2. Longshore drift moves material along a coastline determined by the prevailing wind.
  1. Where the coastline changes direction the material is carried on being deposited into the sea
    1. The increase depth of water will stop it reaching the other side of mainland
      1. Refraction (waves bending) and a different wind direction can cause a curved end
      2. If a spit does join the other side of land it forms a bar
3. Behind the spit is very low energy waves meaning finer silt and mud is deposited which can be colonised by vegetation to form a salt marsh
4. Spurn head, Humberside
Sand dunes
1. Psammosere - succession that develops on sand
2. Accumulations of sand shaped into mounds by the wind
3. Dry wide sandy beaches
  1. Strong onshore winds to transport sand particles through saltation
    1. An obstacle traps the sand when deposited behind is as the wind's energy reduces
4. Knoll Beach, Isle of Purbeck, Dorset SW England
5. Issues
  1. Home to rare species of plants and birds
    1. Vulnerable areas are planted with marram grass to stabilise the dunes
  2. Fire hazard - BBQ's and cigarette ends
    1. Fire beaters are positioned within the dune area
  3. No tourist facilities
    1. Toilets, shops and a car park was built
    2. Litter bins
  4. Picturesque - lots of tourists
    1. Board walks have been laid through the dunes to keep tourists off the dunes
    2. Information boards to educate tourists about the environment
Salt marshes
1. muddy shore between neap tide & extreme spring tid
2. Halosere - succession in a salt marsh
3. Low energy environment & mud
4. creeks - formed by the erosive power of the water draining back to the sea at falling tide
5. Coastal defence - acts as a big sponge
  1. Many new salt marshes are being created due to managed retreat e.g. Essex
6. Threats
  1. Industry
  2. Being drained for agriculture
  3. Eustatic change
  4. Isostatic change
Tombolos
1. Waves refract around the island resulting in low energy behind the island
  1. Material is deposited
    1. Joins to the land

Próximo

Descrição

Resumo de Recurso

Semelhante

	Criado por maddiemurchie23 mais de 11 anos atrás