Chapter 4 : Coasts Flashcards
(23 cards)
What is longshore drift?
The process of which sand is carried parallel to the shore.
Name 4 ways waves wear away the coast.
- Attrition
- Hydraulic action
- Abrasion
- Solution
What is hydraulic action?
When water if forced into the cracks of the rock, breaking it up.
What is abrasion?
When sand and pebbles wear away the rock like sandpaper.
What is solution?
When soluable material is dissolved form the rock.
What is attrition?
When rocks and pebbles knock against eachother, breaking eachother down into smaller pieces.
In what kind of pattern is material carried along the coastline?
In a zigzag pattern.
How does a wave-cut platofrm form?
- The waves carve wave-cut notches into cliffs at a headland.
- They get deeper until the rock above them collapses, letting the sea carry the debris away.
- The process repeats non-stop, leaving a wave-cut platform behind.
How does a cave form?
The sea attacks crack in the cliff at headand. The cracks grow larger and form a cave.
How does an arch form?
When a cave is eroded all the way through, turning it into an arch.
How does a stack form?
When an arch collapses, it leaves a stack.
How does a stump form?
Over time, a stack is eroded, turning it into a stump.
What is a sea wall?
They are curved walls used to reflect the waves away.
What is a arock armour?
Big rocks that soak up the waves’ energy so it slows down erosion.
What is an artificial reef?
Rocks that are built up at sea to break waves and absorb their energy.
What are reventements?
Fences that blocks waves from battering against the cliffs.
What are groynes?
They are structures that stop sand from being carried away becasue sand absorbs the waves’ energy.
What is beach nourishment?
When sand or shingle is added to the beach because sand absorbs the waves’ energy.
Name 4 coastal defences that reduce wave energy.
- Groynes
- Revetements
- Artifical Reef
- Rock armour
Explain why reducing the energy of waves helps to slow down coastal erosion.
If the waves have lesser energy, they won’t have the power to erode cliffs and the damage will be reduced.
What coastal defence is designed to prevent water from flooding into the buildings?
Sea wall
Describe how sand forms.
Larger chunks of rocks are broken down into small grains through eriosion. The process repeats until it is broken down into small grains, which is sand.
Which type of coastal defence is the most expensive?
Sea wall.
