The Coastal Zone Flashcards
Tuvalu is an island based on what?
Fossilised coral
Tuvalu’s highest point
4.5 metres
Tuvalu is located where?
Polynesia
IPCC’s predictions for global sea level rise
- 18 to 0.38 metres by 2100 (best)
0. 26 to 0.59 metres (worst)
The IPCC stands for what?
Intergovernmental panel on climate change
The three main reasons why sea levels are rising
Thermal expansion
Ice sheets and glaciers melting
Post glacial rebound
The four main land forms on a coastline’s headland
Caves, arches, stacks, stumps
The fancy name for the creation of bays
Embayment
This name is given to water when it batters the coast to form a bay
Wave attack
Formation of a bay:
1) soft rock is usually located in-between pieces of hard rock on a coast
2) soft rock erodes faster than hard rock.
3) when hydraulic action erodes the soft rock, it wears away. Whereas the hard rock on the headland does not erode as fast
4) the speed of erosion then exponentially grows
5) when the erosion happens for long enough, a bay is formed
What forms faults in rocks
Waves and geographical movement
What breaks into faults in rocks and creates caves?
Salty water breaks into the cracks on the headland and corrodes the stone. The stone then becomes unstable and is hydraulically removed by the sea.
A stump was originally what before it was weathered
A stack
A fault is basically…
A crack in a stone
When caves are eventually eroded through, they produce a what?
Arch
Formation of a wave cut platform
1) hydraulic action erodes bottom of cliff
2) cliff falls in mass movement
3) rock and sediment falls to seabed
4) sediment and rocks compress under the weight of the water
5) over time the sediment turns to rock
6) this is called a wave cut platform
This is the name for when water and stone abrades ( + hydraulic action) the coast leaving an indentation on the side of the cliff. It is usually located at the height of the waves after a wave cut platform
Wave cut notch
Land forms of deposition
Spits, bars, tombolos, beaches
When the earth takes in heat from the atmosphere and expands due to the sheer temperature
Thermal expansion
Longshore drift acts in the direct of…
The prevailing wind
Back wash always returns from the coast at what angle?
90 degrees
This is the name for the movement of water onto the coast
Swash
This the name for the returning of water to the sea from the coast after it has hit the shoreline
Back wash
The formation of a spit
1) longshore drift transports sediment down coast
2) a change in shape of land means sediment is deposited away fro. The coast
3) a longer tongue of sediment build up, known as a spit. The end is then curled by the wind.
4) salt marshes are then formed in sheltered area of the bay
An example of a spit in the UK
Hurst Castle, Hampshire
An example of a bar in the UK
Slapton Sands, Devon
An example of a tombolo in the UK
Chesil beach, Dorset
Formation of a bar
1) longshore drift moved by prevailing wind
2) initially a spit will form
3) spit merges with the other side of the bay
4) effectively, a dammed area of water is created known as a lagoon
Formation of a tombolo
1) longshore drift creates a spit
2) spit reaches out to island
3) sediment is deposited due to little energy
4) spit and island merge, creating a tombolo
These are created when water loses energy behind a spit and deposits its contents
Salt marsh
When the earth take in energy from the atmosphere and gets bigger, rising the water levels.
Thermal expansion
Floodplains are usually used for…
Farming/agriculture
Farming in flood plains has a bonus and drawback. Name them.
+ when a river floods it means nutrients and helpful sediment is deposited in the soil which helps plants grow
-when a river floods, it usually damages any current crops growing.
The human caused reason why Tuvalu is in trouble
We cause global warming
When salt water enters the land and leaves the soil in a bad condition.
Salt water intrusion
Amount of Tuvaluan’s forced to migrate to New Zealand
4,000
The highest tide Tuvalu recieves is getting higher but what amount ever year?
5mm every year
Reactions to the possibility of Tuvalu submerging
+ Tuvalu Protocol
+ Planned evacuation for 10,000 people
+ Aid has been recieved from New Zealand
The name of concrete pillars stretching out into the ocean to reduce longshore drift
Groynes
This is created to buffer and absorb wave energy. This reduces the risk of flooding
Marshland
These also buffer sand and reduce the wave energy but they involve incredibly a lot more sand
Dune regeneration
The name given to the wave protection which involves large rocks being placed on the beach to reduce wave energy
Rock armour
When homes are moved further inland and land turns to agricultural use to prevent flooding.
Managed retreat
These deflect any waves and sediment from entering towns and villages across the coastline
Sea walls
When a beach is artificially extended to absorb wave energy
Beach nourishment
The name given to the problem when sand builds up even more after a beach groyne
Terminal groyne syndrome
Name given to the strong winds and rain which erodes mud and rock on the coastal areas
Attack from above
Cost of Lyme Regis’ redevelopment
£21 million
Name given to the temporary ugliness of a redevelopment
Eye sore
This was the approximate ratio of money spent to money gained in Lyme Regis after its redevelopment.
1:6 (spent:returned)
This is the name of mud and soil being artificially attached to a harder surface underneath I.e. Limestone
Soil nailing
How many piles have been inserted into the ground in Lyme Regis?
1,000
Ways in which Lyme Regis has prevented shoreline erosion
Extended the Cobb (to shelter the bay)
2 groynes inserted (to prevent longshore drift)
Install rock armour (to break the waters energy)
Strengthen the sea wall (to make sure is can withhold a high energy storm)
The name of the hard rock under the limestone in Lyme Regis which does not absorb water
Black Ven Marl
Waves are formed by the…
Wind
When waves reach a coastline, … Slows the bottom of the wave down and makes the surface topple over the bottom.
Friction slows the bottom of the wave down
An island which is famous for large waves due to its volcanic origins leaving the location with a very steep ocean bed (depleting the time and distance for friction the slow the wave down)
Hawaii
