G3 WJEC Alevel geography everything you need to know for 1.1 including case studies
1.1 what is a coasteal system and what are the dynamics of coastal environments.
G3 WJEC Alevel geography everything you need to know for 1.1 including case studies
Teacher recommended
?- Created by: Maxine La Grange
- Created on: 30-05-13 11:52
View mindmap
- 1.1what is a coastal system and what are the dynamics of coastal environments
- the coastal system
- one of:
- inputs
- outputs
- two systems:
- cliff system
- inputs
- sub areal processes
- weathering
- atmospheric process
- wind erosion
- sub areal processes
- outputs
- sediment at base of cliff
- either deposited
- through marine processes
- or transported
- through marine processes
- either deposited
- sediment at base of cliff
- inputs
- beach system
- input
- sediment
- from longshore drift
- the cliff
- offshore
- sediment
- throughput
- longshore drift
- output
- longshore drift
- destructive waves
- carry sediment offshore
- input
- cliff system
- one of:
- coastal sediment cells
- areas of coast usually defined by headlands within which marine processes are largely confined
- with limited transfer of sediment from one cell to another
- very in size depending on the nature of the coast
- there are 11 sediment cells around England an wales
- no1: st,Abbs Head
- no11:solway firth
- areas of coast usually defined by headlands within which marine processes are largely confined
- the state of dynamic equilibrium in the coastal system
- the relationship between inputs and outputs is constantly changing
- dynamic
- therefore
- system works towards an equilibrium position where input equal outputs
- therefore
- dynamic
- the relationship between inputs and outputs is constantly changing
- wave types and characteristics and their variations over time and space
- two extreme forms of wave:
- have different characteristics
- length
- height
- velocity
- frequency
- stays thesame
- occur in different places determined by local configuration of the coastline and or prevailing wind conditions
- constructive
- lower
- less
- up to 100m
- 8-10sec
- 6-8 waves/min
- frequency
- low/high energy
- beach gradient
- strong swash or backwash
- beach gradient
- low/high energy
- low
- shallow
- strongest swash
- strong swash or backwash
- carries sand and shingle up beach
- contribute to the formation of beach ridges and berms
- beach gradient
- strongest swash
- low/high energy
- shallow
- frequency
- wave period
- frequency
- frequency
- 6-8 waves/min
- wave length
- wave period
- wave period
- 8-10sec
- wave steepness
- wave length
- wave length
- up to 100m
- wave height
- wave steepness
- wave steepness
- less
- lower
- destructive
- higher
- more
- 20-40metres
- 5-6sec
- 10-14waves/min
- high
- deep
- backwash
- due to plunging motion it generates little swash but more powerful backwash
- transports sediment down beach face
- resulting in a net loss of material
- plunging breakers, beer, East Devon
- transports sediment down beach face
- due to plunging motion it generates little swash but more powerful backwash
- backwash
- deep
- high
- 10-14waves/min
- 5-6sec
- 20-40metres
- wave height
- more
- tend to occur during storms
- higher
- have different characteristics
- slow down,shorten, gain height
- fetch
- maximum distance of open water over which wind can blow
- swell waves
- shallow gradient waves with long fetch + wavelength
- most beaches experience alternating action
- constructive waves in summer
- destructive waves in winter
- resulting in annual cycle of beach growth and decay
- constructive waves in summer
- resulting in annual cycle of beach growth and decay
- wave refraction
- concentrates wave energy on headlands
- causes erosion on headlands therefore provide shelter to bays therefore negative feedback
- hardrock
- dissipates energy in bays
- causes disposition
- bays have soft rock
- therefore it should erode quicker
- but due to refraction of wave
- high energy waves hit headlands
- therefore create negative feedback
- high energy waves hit headlands
- but due to refraction of wave
- therefore it should erode quicker
- Holderness Coast
- north sea coast between scarborough and whitby
- upland coastline
- weaker Lias shales form bays
- more resistant Jurassic sandstones and limestones form headlands
- orthongonal waves refract around headlands
- causing orthogonals to converge
- bringing more energy per metre of headland than of bays
- causing orthogonals to converge
- concentrates wave energy on headlands
- two extreme forms of wave:
- the coastal system
Comments
Report