Coastal Environments in the UK Flashcards
What factors affect wave size
Wind strength
Fetch
Time Wind has blown for
What is prevailing wind
The most prominent wind direction at a specific time
What is the prevailing wind in the UK
SW
How does wind strength affect wave size
The stronger the wind, the greater the friction on the sea, the bigger the wave
How does wind duration affect wave size
The longer the wind has been blowing, the more energy is transferred to the surface of the sea, the bigger the wave
Why do waves break
Friction slows the base of waves whilst the top maintains its speed
This causes the top of the wave to topple over the base
What is swash
The movement of the wave up the beach
What is backwash
Gravity moving the wave down the beach
What are constructive waves like
Shallow
Low energy
Strong swash, weak backwash
What do constructive waves do
Build up the beach by depositing material in the swash
What are destructive waves like
Steep
High energy
Weak swash, strong backwash
What do destructive waves do
Erode the beach by dragging material in the backwash
What is coastal erosion
The loss of land and/or the removal of material along the coastline as a result of destructive waves and other hydrological processes
How does hydraulic action work
Waves force water into cracks in rocks, this compresses the air inside
This explosive action of trapped air in a rock is called cavitation
Cavitation leads to loose sediment entering the ocean.
How does attrition work
Kinetic energy transferred to rocks by waves causes the rocks to swash into each other
These rocks get broken up and worn down and eventually end up on the shore
How does solution work
Seawater is slightly acidic and can dissolve material from the coastline
This is particularly apparent in limestone and chalk as they contain calcium carbonate which is easily dissolved
How does abrasion work
Waves smash rocks into the coastline
This causes the coastline to be worn away and chipped
What is coastal transport
The movement of sediment, eroded from the coastline, by waves
What determines how sediment is transported
The size of the sediment
How does solution transport material
Dissolved material is carried along the coastline by waves
How does saltation transport material
Small pebbles moving along the seas floor by hitting each other
How does suspension transport materials
Fine sediment is suspended in the water and moved with the direction of the waves