Component 2 - Coastal Change and Conflict Flashcards
What are the 3 types of mass movement?
1.Slides - material shifts in a straight line
2.Slumps - material shifts with rotation
3.Rockfalls - material breaks up and falls down the slope
What are examples of mechanical weathering?
1.hydraulic action
2.abrasion
3.attrition
What is chemical weathering?
The breakdown of rock by changing its chemical composition, eg carbonation weathering
What is hydraulic action?
waves crash against the rock and compress air in the crack, causing pressure to build, breaking a piece off/
What is abrasion?
eroded particles in the water scrape and rub against rock,
What is attrition?
eroded particles in the water smash into eachotehr becoming smaller. Their edges get rounded off too
What is a discordant coastline?
When the coastline is made up of alternating bands of hard and soft rock, at right angles to the coast
What is a concordant coastline?
the alternating bands of hard and soft rock are parallel to the coast
What landforms are made at discordant coastlines and why?
1.bays and headlands are formed
2.because the bands of rock are being eroded at different rates.
How does the UK’s climate impact its coastlines?
1.Strong winds cause destructive waves which increase erosion of cliffs
2.Intense rainfall makes cliffs more saturated so mass movement occurs more.
3.The prevailing winds from the south west bring storms in, which batter the coast and erode it
What are the properties of destructive waves?
1.large, steep and have a high frequency (10-14 a min)
2.Their backwash is more powerfu than their swash, so they remove material from the coast.
How do waves erode cliffs?
1.The wave forms a wave cut notch by erosion
2.The rock above becomes unstable and collapses
3.This material is washed away and the cycle continues
4.This causes cliffs to reteat.
5.It also leaves a wave cut platform
How are headlands eroded?
CCASS
1.Waves crash into the headland and enlarge cracks by hydraulic action and abrasion
2.this continues until a cave forms
3.This continues until it breaks through the headlands and forms an arch
4.Erosion weathers away the rock supporting the arch, causing it to collapse
5.This forms a stack, which is then further eroded into a stump, causing the headland to retreat
What is LSD?
Long shore drift - 1.Waves follow the prevailing wind
2.This means they usually hit the coast at an oblique angle
3.The swash carries material up the beach, with the waves
4.The backwash then carries it at right angles back out.
5.This repeats and carries material down a coastline
What is deposition?
When material being carries by water is dropped on a coast.
What are the properties of constructive waves?
1.They deposit more than they erode
2.They are low, long and have a low freq.(6-8waves)
How are spits formed?
1.LSD transports material down a coast, until it arrives at a sharp bend
2.The waves lose their energy and deposit material here
3.This continues until a spit forms.
4.Strong winds and waves can form a recurved end at the end of a spit.
What happens to the land behind a split?
it becomes sheltered, so lots of material accumulates and plants begin to grow. This then becomes a salt marsh.
How are bars formed?
1.When a spit joint 2 headlands togther
2.It cuts off the bay from the sea, forming a lagoon
BIG WARNING - CHECK OS MAP LABELS BEFOREHAND PLS
yoko geri - side thrust kick
How does agriculture affect the coast?
1.Agricultural land is of low value, so is left unprotected meaning that it is left to be eroded by the sea
2.Clearing vegetation for crops exposes the soil, making it vulnerable to weathering
3.marshland is often drained for use, this removes a natural flood barrier
How does development affect the coast?
1.Coasts with lots of settlement have more coastal defences so they erode slower there
2.This means that tranportation and deposition of material along the coast is change, so places along the coast may get more or less deposition
How does industry affect the coast?
- Coastal quarries expose lots of rock, making it exposed to erosion and weathering
- Gravel is taken from beaches to use in construction. This means there is less to protect the coast.
How does climate change and rising sea levels increase the risk of coastal flooding and erosion?
1.It will cuase higher tides, sos coastal areas flood more often
2.Higher tides remove larger amounts of material from beaches, leading to more erosion