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Description
Flashcards by Fxxxxxx Hxxxx Rxxxxx, updated more than 1 year ago
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Created by Fxxxxxx Hxxxx Rxxxxx
over 5 years ago
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| Question | Answer |
| Define erosion | Wearing away of rocks |
| Define weathering | Physical breakdown of rocks |
| Define mass movement | Large scale downward movement of rocks and materials |
| Define transportation | When eroded and weathered material are carried in water. These materials are deposited when the waves loses its energy |
| Define hydraulic action | Hydraulic action is the sheer power of waves crashing against the cliff and air becomes trapped causing the rock to break |
| Define abrasion | Abrasion is when rocks are thrown at the cliff |
| Define attrition | Attrition is when rocks grind against each other becoming smoother and more rounder |
| Define solution | Solution is when sea water dissolves certain types of rocks |
| Define freeze thaw weathering | Takes place when water collects in a rock and freezes. This causes the rock to expand and widen the crack. The water then melts and goes deeper into the crack. This process repeats until the rock is fully broken |
| Define chemical weathering | Chemical weathering is acid rain. Rain water is slightly acidic and it causes a weak chemical reaction to take place causing the rock to weaken and break down |
| Define biological weathering | Biological weathering takes place when roots of growing plants and trees widen cracks and burrowing animals and nesting birds can cause rocks to weaken and decay |
| Define slumping | Slumping occurs after long periods of rainfall. Water seeps into the permeable rocks and where permeable rock meets impermeable rock, the saturated soil slumps along the surface |
| Define sliding | Sliding is similar to slumping but the movement of rocks occurs along a flat surface and large amounts of soil and rock move down rapidly causing a lot of damage |
| Define traction | Traction is when pebbles and larger sediments are rolled along the sea bed as they are heavy |
| Define saltation | Saltation is when small pieces of shingle or large sand grains are bounced as they are not heavy enough to sink or light enough to float |
| Define suspension | Suspension is when small particles are carried in the water such as silt and clay |
| Define solution | Solution is when minerals are dissolved in seawater and the load is not visible |
| Define concordant coasts | Rocks run parallel to the coastline |
| Define discordant coasts | Rocks lie at right angles to the coastline forming headlands and bays |
| Define waves | Waves are generated by wind blowing over the sea. The friction with the surface of the water causes ripples to form which grows larger into waves |
| Define constructive waves | Constructive waves helps build material on the beach and has a strong swash and a weak backwash. They are formed in calm weather |
| Define destructive waves | Destructive waves removes material from the coastline and has a strong backwash and a weak swash. They are formed in storm conditions |
| What are the factors affecting waves | Wind strength (speed): the stronger the wind the greater the friction on the sea surface, therefore the bigger the wave Wind duration: length of time wind blowing Fetch: the distance of open water which the wind has been blowing. The longer the fetch, the more powerful the wave |
| What are the effects of stormy weather | Coasts are subject to strong winds, increasing the eroding power of the waves, and heavy rainfall contributes to mass movement Frequent storms can damage coastal landform Beach sediment can be removed from a section of coastline Sand dunes can be removed from storms |
| How does UK's climate affect coastal erosion and recession | Prevailing winds from the south-west brings warm moist air from the Atlantic and frequent rainfall, which contributes to weathering and mass movement The four seasons have different impacts on coastal erosion. For example, cold temperatures in winter leads to freeze-thaw weathering |
| Describe the diagram of headlands and bays | |
| Describe the formation of headlands and bays | Limestone outcrops to form headlands because it is harder and more resistant. Limestone is also a harder sedimentary rock than clay. Clay forms bays because it is less resistant and more softer. Hydraulic action and abrasion erodes the cliff and this causes the clay to erode and go inwards forming headlands and bays |
| Describe the diagram for wave cut platforms | |
| Describe the formation of wave cut platforms | Weather weakens the top of the cliff and the sea attacks the base of the cliff causing it to undercut and form a wave cut notch. The notch increases in size causing the cliff to collapse. Destructive waves causes the backwash to carry the material back towards the sea forming a wave cut platform. The process repeats and the cliff continues to retreat |
| Describe the diagram for caves, arches, stacks and stumps | |
| Describe the formation of caves, arches, stacks and stumps | A large crack is opened up by hydraulic action. The crack erodes more forming a cave and the cave becomes larger. The cave breaks through the headland forming a natural arch and the arch is eroded and collapses when it becomes unstable. A stack is then formed and this is eroded forming a stump |
| Describe the diagram for bars | |
| Describe the formation of bars | A bar is a ridge of sand or shingle across the entrance of a bay or river mouth. Fresh water is trapped behind it forming a lagoon. The formation is similar to a spit but material is transported by longshore drift until it is deposited from one side of a headland to another |
| Describe the diagram for spits | |
| Describe the formation of spits | A spit is a long narrow ridge of sand and shingle where one end is attached to the land and the other projects out into sea. Spits are formed due to longshore drift which is the movement of material along a beach transported by wave action. Prevailing winds (strongest winds) causes the swash to meet the land at 45 where material is deposited. However, the backwash at 90 causes the material to go back out into the water under the influence of gravity. This process is repeated in a zigzag motion. When the sediments start to be deposited out in the water, the spit curves due to the change in the wind's direction and water flowing from the estuary causes the spit to end. Salt marshes can develop behind spits because it is sheltered and so silt and mud are deposited |
| Define hard engineering | Hard engineering involves building artificial structures and physically changing the landscape. It is more effective but expensive |
| Define soft engineering | Soft engineering takes a more natural approach and is more environmentally sustainable. It is cheap but not as effective |
| Define sea walls | Sea walls are concrete walls that are placed at the foot of a cliff. They are curved to reflect the energy back into the sea |
| What are the advantgaes of sea walls | Extremely effective at stopping erosion and they have promenades and walkways so people can walk along them It also acts as a barrier to stop flooding |
| What are the disadvantages of sea walls | Waves are still powerful and can break down or erode the sea wall and they are expensive to build as they are made out of concrete It also needs replacing every 25 years |
| Define groynes | Groynes are long timber blocks that are built at right angles into the sea to stop longshore drift |
| What are the adavantages of groynes | Materials are deposited forming beaches which encourages tourists It traps sediments carried by longshore drift and this means that waves can erode the beach and not the coast Relatively cheap |
| What are the disadvantages of groynes | Starves beaches further down the coastline increasing rates of erosion elsewhere Looks unattractive |
| Define rip rap | Rip rap are large boulders placed at the foot of the cliff and they break the waves and absorb their energy |
| What are the advantages of rip rap | Cheaper than sea walls and are easy to maintain They can be used for fishing and looks natural They are also cheap and lasts long |
| What are the disadvantages of rip rap | Rocks are expensive to transport and sometimes the rocks look different to the local geology affecting tourism It can also stop access to the beach |
| Define beach nourishment | Beach nourishment is when sand is pumped onto existing beaches |
| What are the advantages of beach nourishment | Blends with the existing beach Builds larger beaches which attracts tourists |
| What are the disadvantages of beach nourishment | Needs to be constantly replaced The sand needs to be brought in from elsewhere which is expensive to transport |
| Define dune regeneration | Dune regeneration is when marram grass planted on sand dunes stabilises the dunes and helps to trap sand to build them up |
| What are the advantages of dune regeneration | Relatively cheap Maintains a natural-looking coastline |
| What are the disadvantages of dune regeneration | Can be damaged by storm waves Area needs to be zoned off from the public, which is unpopular |
| Define managed retreat | Managed retreat is the controlled flooding of low-lying coastal areas |
| What are the advantages of managed retreat | Cheap and it creates salt marshes which can provide habitats for wildlife Natural defence against erosion |
| What are the disadvantages of managed retreat | Land is lost as it is reclaimed by the sea Landowners need to be compensated |
| Define do nothing | Nothing is done and the coast is left to be eroded |
| What are the advantages of do nothing | It is natural |
| What are the disadvantages of do nothing | Disadvantages are that land is lost and insurance companies refuse to insure their homes and businesses |
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