Coastal Landscapes in the UK Flashcards
Where are the UK’s main upland areas located?
North and West of the country
What type of rock are upland areas made from [1] and why [1]?
- Igneous and metamorphic rock
- Resistant to erosion
Where are the UK’s main lowland areas located?
South and East of the country
What type of rock are lowland areas made from [1] and why [1]?
- Sedimentary rock
- Erode more easily
UK cities are often located on what features? [2]
- Lowland areas
- On the UK’s main rivers
Describe the process of hydraulic action [3]
- Waves crash against rock and compress the air in cracks
- This puts pressure on the rock
- Repeated compression widens the cracks and causes bits of rock to break off
Describe the process of abrasion
Eroded particles in the water scrape and rub against rock, removing small pieces
Describe the process of attrition
Eroded particles in the water collide, break into smaller pieces and become more rounded
Describe traction
Large particles like boulders are pushed along the sea bed by the force of the water
Describe saltation
Pebble-sized particles are bounced along the sea bed by the force of the water
Describe suspension
Small particles like silt and clay are carried along in the water
Describe solution
Soluble materials dissolve in water and are carried along
Describe how longshore drift transports sediment along a coast [5]
- Waves follow the direction of the prevailing wind
- They hit the coast at an oblique angle (not 90°)
- The swash carries material up the beach, in the same direction as the waves
- The backwash then carries material down the beach at right angles, back towards the sea
- Over time, material zigzags along the coast
When does deposition occur?
When water carrying sediment loses energy and slows down
THINK: deposition
When do coasts build up?
When the amount of deposition is greater than the amount of erosion
When does the amount of material being deposited increase? [2]
- Lots of erosion elsewhere on the coast (more material available)
- Lots of material is transported into the area
What are the two types of weathering?
- Mechanical weathering
- Chemical weathering
What is mechanical weathering?
The breakdown of rock without changing its chemical composition
What is an example of mechanical weathering?
Freeze-thaw weathering
Describe how freeze-thaw weathering occurs [5]
- Happens when the temperature alternates above and below 0°
- Water enters cracks in rock
- When the water freezes it expands, which puts pressure on the rock
- When the water thaws it contracts, which releases the pressure on the rock
- Repeated freezing and thawing widens the cracks and causs the rock to break up
What is chemical weathering?
The breakdown of rock by changing its chemical composition
What is an example of chemical weathering?
Carbonation weathering
Describe how carbonation weathering occurs [4]
- Rainwater has carbon dioxide dissolved in it
- This makes a weak carbonic acid
- Carbonic acid reacts with rock that contains calcium carbonate
- So these rocks are dissolved by the rainwater
What is mass movement?
The shifting of rocks and loose material down a slope
THINK: gravity
When does mass movement occur?
When the force of gravity acting on a slope is greater than the force supporting it
What does mass movement cause coasts to do?
Retreat rapidly
When is mass movement more likely to occur?
When the material is full of water - water acts as a lubricant and makes the material heavier