Coasts 1 Flashcards
What words to use for system (10)
Dynamic equilibrium,
Energy,
Open/closed
Input
Output
Feedback loops
Sediment
Processes
Store
How does thermal energy affect coastline
From the sun
Weathering
Heating and cooling = expanding…
High temp increases rate of reaction
How does chemical energy affect the coastline
From the sun
Photosynthesis
Biological weathering
How does GPE affect the coast
Movement caused by virtue of height
Mass movement - releases energy
How does kinetic energy affect the coastline
Wind from sun
Wind imparts kinetic energy to waves
What are open and closed systems
Open - sediment enter and leave freely
Closed - sentiment can’t enter and leave freely
What’s matter
Clay
Sand
Pebbles
Boulders
What’s happening on a dynamic coastline ( inputs ) (5)
Fluvial imputed
Offshore inputs
Cliffs
Human
Aeolian
What’s happening on a dynamic coastline ( outputs )
Pulled offshore
Humans
Aeolian
Coastal features
What’s feedback in coastal system
Inputs = outputs
Equilibrium
If this is disturbed it will self regulate
Negative and positive feedback
N - reduce change
p- increase change
How many sediment cells in England
11
What are sediment cell boundaries determined by
Physical features
Topography
What are sediment cells used for
To manage coastlines more affective and to reduce the possibility of consequences affecting other areas
SUBCELL 2A
What are the 2 boundaries
Flamborough head to sunk island
SUBCELL 2A
What are the 3 sources and how much
Flamborough head
Smithic sands
Soft boulder clay
3million m*3 a year
SUBCELL 2A
What’s the outputs
Sunk island
Humber estuary
PHYSICAL FACTORS AFFECTING COASTLINE ( WIND )
How does fetch affect
The distance over which the wind has blown - longer fetch = higher waves
PHYSICAL FACTORS AFFECTING COASTLINE ( WIND )
How does the fetch influence the uk
The uk has a wet and mild climate due to travelling over a long time from a warm climate ( Atlantic Ocean )
PHYSICAL FACTORS AFFECTING COASTLINE ( WIND )
HOW DOES IT INFLUENCE COASTAL SYSTEM ( actual question )
- wind imparts energy via frictional drag
- longer fetch = higher waves
- higher waves = destructive causing erosion and a sediment imput
- the direction of wind eg: sw in uk meaning warm and moist wind increases chemical weathering and oxidisation
PHYSICAL FACTORS AFFECTING COASTLINE ( WAVES )
What’s the relationship between wave height and wave energy ( stats )
Non liner
Eg Atlantic wave height = 5 and the energy = 200
Channel wave height is 0.6 and the energy = 2.1
PHYSICAL FACTORS AFFECTING COASTLINE ( WAVES )
How does it influence coastal system ( actual question )
- Long fetch = more energy for frictional drag
- higher waves and energy = erosion
- erosional features + mass movement
PHYSICAL FACTORS AFFECTING COASTLINE ( TIDES )
What’s are the names of the tides
Coming in = flooding tide
Goes out = ebbing tide
PHYSICAL FACTORS AFFECTING COASTLINE ( TIDES )
How are tides influenced + example
Moons gravity pulls on water influencing waves
Funnel bays influence tidal magnitude e.g. bay of fundy 15m
PHYSICAL FACTORS AFFECTING COASTLINE ( TIDES )
What’s happens to coasts with higher tidal range
More erosion - water can reach higher and lower
E.g. salt crystallisation weathering
PHYSICAL FACTORS AFFECTING COASTLINE ( TIDES )
How does the tide influence the coastal system ( actual question )
- flooding tides bring energy and sediment
- ebbing tides take sediment and energy away
- higher tidal range = increased impact
PHYSICAL FACTORS AFFECTING COASTLINE ( SURFACE CURRENTS )
what are the features of surface currents
- large scale
- wind driven via frictional drag
- 100M deep
PHYSICAL FACTORS AFFECTING COASTLINE ( SURFACE CURRENTS )
Example of surface current
Gulf Stream originating from tropical Atlantic - fast current bringing heat
PHYSICAL FACTORS AFFECTING COASTLINE ( SURFACE CURRENTS )
How does it affect coastal system ( actual question )
- bring sediment from long distances and also takes away
- Gulf Stream brings thermal energy = increases ROR and oxidation of iron within sand
PHYSICAL FACTORS AFFECTING COASTLINE ( RIP CURRENTS )
Features and what are they
- strong localised narrow current of water, moving directly away from the shore, cutting through breaking waves
PHYSICAL FACTORS AFFECTING COASTLINE ( RIP CURRENTS )
What can they do
Modify coastlines - by forming cups
PHYSICAL FACTORS AFFECTING COASTLINE ( RIP CURRENTS )
How do they affect the coastal system
Take large amounts of sediment away from a location area
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
what types of structures are there and describe them
complex = faults, joints,bedding planes - this increases chancea of erosion by hydraulic action
- porosity - holes within
- permeability - holes connected within = more prone for mass movements
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
whats the different types of geology
- structure
- lithology
- discordant
- strata
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
how does lithology affect coastline , 2 examples
- the physical and chemical composition
pembookshire - basalt = strong interlocking crystles - less sediment imput, resistant to erosion
walton - london clay and red crag = soft rock - vunerable for erosion - has more depositional features
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
how does strata affect coastline ( 3 )
- horizontal strata
- seawood dipping
- landwood dipping
can evaluate that strata is not important for sediment but is for topography
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
how does discordant coastlines affect the coast
- alternating hard and soft rock
the waves are refracted onto the headlines meaning more erosion occours to form e.g. stacks and stumps
energy drops in bays and therefore more depositional features e.g beaches
PHYSICAL FACTORS AFFECTING COASTLINE ( GEOLOGY )
how does geology alter the coastline ( actual question )
low sediment
- less complex structure
- hard lithology
- strata not important
high sediment
- complex structure
- soft lithology
- discordant coastlines
EROSION
what does gromorphic and erosion mean
geomorphic - relating to the formation and shaping of landforms and landscapes by natural processes
erosion - the wearing away and/or removal ove any rocks and other material by a movisng force
EROSION
marine processes - erosion techniques
marine = waved influenced processes
abrasion - rocks hitting cliff
HA - waves into cracks - air compressed
attrition - rocks hitting one another
solution - acidity of the water
EROSION
marine processes - transportation techniques
solution - disolved particles
suspesion - carrying
saltation – bouncing
traction - rolling
EROSION
marine processes - deposition facts, settling velocity
- input of sediment is greater then the output
- lower energy areas means more deposition e.g. estuary, lee of headlands e.g. smithic sands
- settling velocity - speed required for suspened particles of a given size, transportated by rivers, wind and tides to be deposited
- heavies sediment deposited first
EROSION
physical factors of significance of marine processes
range - difference between high and low tide, higher tidal rand = more energy
wave energy - increased wave energy from frictional drag
geology - lithology, complexity, discordant coastlines
WEATHERING
subarial process - difference between weathering and erosion
weathered materia doesnt need to be moved away , unlike erosion
WEATHERING
subarial process - mechanical processes and area ( 4 )
- high latitude
processes:
- freeze thaw
- thermal expansion
- pressure release - rocks under high pressure = flaking
- salt crystalisation
WEATHERING
subarial process - chemical processes and area
tropics - high temp and moisture
- rust/oxidation
- carbonation = limestone ( calcium carbonate ) dissolved by weak acids e.g. cabonic acid
vant holts law = increased 10 degrees celcius increased chemical reaction
