all of coasts Flashcards
What is the littoral zone?
the coast, the barrier between sea and land
What are key features of high energy coasts?
- destructive waves
- storm conditions
- long fetches
- erosion and transport
- wave cut platforms
What is an example of a high energy coast?
Atlantic Coasts e.g. Scotland
What are key features of a low energy coast?
- constructive waves
- deposition and transport
- beaches
- spits
- lowland coasts
What is an example of a low energy coast?
East Anglian Coast
Where do salt marshes develop?
- sheltered areas where deposition occurs
- where salt and fresh water meet
- no strong tides or currents that would prevent sediment, deposition or accumulation
How do salt marshes develop?
- as mud flats develop, salt tolerant plants begin to colonise and stabilise them
- these species (halophytes) help slow tidal flow and trap more mud and silt
- as sediment accumulates, the surface dries and different plants begin to colonise
- creeks divide up the marsh from water flowing across the estuary at low tide
What is the order of sand dunes?
1) embryo dune
2) fore dune
3) yellow dune
4) grey dune
5) dune slacks
6) mature dune
What can depressions in a dune lead to?
dune slacks which are damp areas
Why do sand dunes need management?
sand dunes are natural sea defences
What is the Norfolk sandscaping scheme?
artificial dune of 2 million cubic meters of sand
How much has the Norfolk sandscaping scheme cost?
£20 million
How are sand dunes managed?
- marram grass stabilises dune
- sea buckthorn stabilises but is invasive
- boardwalks to stop footfall erosion
- fencing slows flow and sand and helps create new dunes
What is the transfer zone?
places where sediment moves along the shore through long-short drift and offshore currents
How do tides and currents affect longshore drift?
- tides change the water levels
- tidal current carriers sediment
- wind direction
How many sediment cells are there in England and Wales?
11
Where does the sediment come from in sediment cells?
- processes of weathering and erosion produce output in the form of sediment
- cliff erosion
- tidal currents carrying sediment
- sand from nearby beaches
- rivers that discharge into the sea bring fine sediment