Physical Landscape Flashcards
Definition of solution
Materials dissolved in water
Definition of suspension
Sand suspended in water
Definition of Traction
Rolling boulders
Definition of saltation
Bouncing pebbles
Definition of freeze-thaw weathering
Water enters a crack, freezes and expands by 10%, when it thaws, more water can enter the crack and so the process continues.
Definition of abrasion
Process where Sand/pebbles in waves rub against the coastline and smooth the surface
Definition of hydraulic action
Waves trap air in cracks in rocks, compressing the air and causing cavitation which expands the crack
Definition of corrasion
Large boulders thrown against the cliff face by the waves
Definition of carbonation
Acids in water dissolved minerals in the rock
How do waves form
Friction from wind blowing over the sea causing ripples that develop into waves
Definition of fetch
It is the distance that wave-generating winds blow across the open water
Why do waves break
As the gradient of the seafloor increases, friction slows the bottom of the wave which causes the crest of the wave to move faster and rise up
(Friction with seabed distorts circular motion, increasingly elliptical orbit as water becomes shallower)
Definition of mass movement
Downward movement or sliding of minerals under the influence of gravity
Key characteristics of constructive waves
Wave crests are far apart
Gently sloping front
Strong swash
Key characteristics of destructive waves
Waves are close together
Steep front
Strong backwash
What is a seawall
- they are at the foot of cliffs/top of beach
- high maintenance
- £10 million per km
- 3-5 metres high
What are groynes
- prevents sediment from being moved down the beach by long-shore drift
- £5000 per metre
- causes higher erosion elsewhere downdrift
What are Rock armour
- rocks against the cliff which forces waves to break therefore absorbing the waves energy
- rocks are expensive to transport
- £1000-£4000 per metre
- obtrusive
What are gabions
- Metal cages filled with rocks
- unattractive
- easy to maintain and last long
- £2000 per metre
What is beach nourishment
- where they build up a beach with sediment from nearby so it blends in
- £3000 per metre
- needs constant maintenance
Dune regeneration
- it is where marram Grass is planted because Dunes are effective buffers for waves and then fenced off so they can grow
- £20 per metre
What is Marsh creation
- allowing low-lying coastal areas to be flooded
- creates habitats
- compensation is given for land so can be expensive