Coasts- The Coastal System Flashcards
What is an input?
Material or energy moving into the system from outside eg.
- precipitation
- fluvial sediment
- wind
What is an output?
Material or energy moving from the system to the outside eg.
- ocean currents
- riptides
- sediment transfer
- evapouration
What is energy (in the coastal system)?
Power or driving force eg.
-the effects of gravity on cliffs and moving air (wind energy transferred to wave energy)
What are stores/components?
The individual elements or parts of a system eg.
- beach
- spits
- bars
- sand dunes
- nearshore sediment
What Are flows/transfers?
The links or relationships between the components eg.
- longshore drift
- erosion
- mass movement
- wind blown sand
What is positive feedback? Give an example
Where a flow/transfer leads to increase of growth eg.
-coastal management such as groynes- trap sediment preventing it from reaching further along the beach, meaning these areas are further deprived of sediment- leading to more erosion elsewhere
What is negative feedback? Give an example
Where a flow/transfer leads to decrease or decline eg.
- when the rate of weathering and mass movement exceeds the rate of cliff foot erosion, a scree slope is formed
- over time, this apron of material extends up the cliff face protecting the cliff face from subaerial processes
- leads to a reduction in the effectiveness of weathering and mass movement
Dynamic equilibrium
When the inputs and outputs within a system are balanced eg.
- constructive waves build up a beach- making it steeper
- encourages formation of destructive waves
- redistribution of sediment offshore by destructive waves reduces beach gradient
- this in turn encourages the waves to become more constructive
- state of constant dynamic equilibrium between the type of wave and the angle of the beach
Terrestrial factors influencing the coastline
- tectonics
- sub aerial processes
- biotic features
- supply of sediment
- fluvial processes
- glaciations
Marine processes influencing the coastline
- fetch
- tides
- wave direction
- sea level change
- wave shape/size
Human intervention influencing the coastline
- industrial and residential development
- sea defences
- pollution
- tourism and recreation
- conservation
Atmospheric factors influencing the coastline
- global warming
- solar energy
- winds
- precipitation
- temperature
What factors affect dynamic equilibrium?
- supply of sand (conservation and protection aim to maintain this)
- sea level changes (also influenced by global warming)
- location of the shoreline (sea defences)
What are landforms?
Individual features which are created by coastal processes eg. stacks, wave cut platforms and spits
What are landscapes?
- the entire are of sea, coastline and immediate land behind the sea front
- within the landscape are characteristic landforms
