Coast 🏝 Flashcards
Define a coastline
A place at which the land meets the sea
What is weathering
The breakdown of rocks at the Earths surface, by the action of rainwater, extreme temperatures and biological activity
How is biological weathering caused
STRONG PLANT ROOTS can force cracks to widen rocks
ANIMALS burrowing and walking along the surface of the ground can weather it away
How is chemical weathering casued
CHEMICAL REACTIONS break down the bonds holding the rocks together breaking them into smaller pieces
How is physical weathering caused
WIND, RAIN & WAVES wear away rocks
FREEEZE-THAW
Give 3 examples of mass movement
Rock falls
Rock/ mud slides
Slumping
What are waves
A body of water moving towards a coastline at a higher than average level
What is backwash
Movement of water always at right angles to the sea
What is swash
Movement goes up at the angle of the wind
What are the characteristics of constructive waves
Strong swash, weak backwash
Created in calm weather
Deposit material
Long wave length, low in height
What are the characteristics for destructive waves
Strong backwash, weak swash Created in storm conditions Erode the coast Short wave length, very steep Occur when energy is high and wave has travelled over a long fetch
What is a headland
Areas of resistant rock which protrude from the coastline
What is a bay
Areas of less resistant rock between 2 headlands which is quickly eroded
How is a wave cut platform formed
Erosion occurs at high (corrosion, solution, hydraulic action)
Undercutting occurs
A wave notch is formed at the base of the cliff
The resulting overhang collapses and the cliff retreats
A large area of flat rock is left at the base of the new cliff line- WAVE CUT PLATFORM
List the order of headland features leading up to a stump
Line of weakness Caves Arch Stack Stump
What is longshore drift
The transport of sediment along a stretch of coastline caused by waves approaching the beach at an angle
How does wave refraction work
As waves approach the coast they are refracted due to the shallow water causing the waves to slow down (friction)
This means their energy is concentrated around the headlines and reduced around the bays
Define the term: beach
The gently sloping area of land between the high and low watermarks
What is a spit
A spit is a finger of land madeof sand and shingle that extends into the sea from the coastline
Name four depositional landforms
Bars Tombolo Dune Beach Spit
Describe the formation of a dune
Sand is blown and deposited when it hits in at obstacle
The sand of builds up overtime to form a ridge at the back of the beach
Vegetation can grow and dunes are formed
Describe the formation of a tombolo 
The spit grows out from the mainland in the direction of longshore drift and connects the mainland with the nearby island
Describe the formation of a beach
Waves approach the coastline parallel to it and their energy decreases as water depth decreases causing constructive waves to deposit material
Describe the formation of a bar
A spit will form and grow across the two headbands in the direction of LSD.
As material is deposited it creates a sandbank and leaves a trapped lagoon behind what’s known as a bar
Define concordant
Where bands of different rock type run parallel to the coastline
Define discordant
Layers of rock run at right angles to the coast
Give three ways you can manage the coast
Doing nothing
Advance the line
Hold the line
What does doing nothing mean for the coast
Letting the sea undertake it’s natural processes
What does ‘holding the line’ mean for the coast
Build protection at the current cliff face to prevent further loss
What does ‘advancing the line’ mean for the coast
Defences aimed at reclaiming small areas of land to assist with protection
What are the benefits of dune regeneration
Cheap (£2000 per hundred metre stretch)
Improves coastal ecosystem
What are the costs of dune regeneration
Can take years for dunes to be established
Need to provide walkways to prevent trampling 
What are the benefits of beach profiling
No new material needs to be found or added
Protects areas behind beach
What are the costs of beach profiling
Expensive (£200,000 per year) due to time and equipment
High crested beaches can seem artificial to visitors
What are the benefits of managed realignment
Sustainable long-term solution especially with rising sea levels
Creates new intertidal habitats
What are the costs of managed realignment
Relies on purchase of land and property to be flooded
Habitats for coastal land-based species are lost due to flooding
What are the benefits of sea walls
Give tourists a nice place to walk along the coast
What are the costs of sea walls
Expensive (£5000 per metre)
Seen as ugly by many
Requires maintenance
What are the costs of beach nourishment
Needs to be replaced regularly
What are the benefits of beach nourishment
Natural appearance
Little environmental impact
Larger beach- more space for visitors
What are the costs of rock armour
Not attractive
What are the benefits of rock armour
Quick build Relatively cheap (£1000-£3000 per metre)
What are the costs of gabions
Have to be replaced regularly
Only work on sand beaches as shingle would break them down
Short life span as steel cages rust
What are the benefits of Gabions
Cheap (£10 a metre)
If made from stainless steel can last 25+ years
What are the benefits of groynes
Life span of 20-30 years Relatively cheap (£5000 each) No maintenance
What are the costs of groynes
Causes issues further down the coast - starving coastline of material
Causes a barrier on beach (users can’t cross)
