Flashcards in Component 2 Topic 4 Deck (30):
How are igneous rocks formed?
Igneous rocks form when molten rock cools and hardens. Igneous rocks are usually old and hard, especially compared to sedimentary rocks. (E.g. granite)
What are sedimentary rocks formed from?
Sedimentary rocks are formed by compacting and compressing lots of sediments into one rock. (E.g. chalk is formed when shells and skeletons of dead sea creatures compress together.)
Describe how metamorphic rocks are formed.
Metamorphic rocks are formed when different types of rock are changed by heat and pressure, therefore creating much harder and compact rocks (e.g. shale becomes slate)
Give two ways in which tectonic activity has shaped the uk landscape.
Active volcanoes and plate collisions have both shaped the uk landscape. The land which is currently the uk us to be much closer to a plate boundary, and active volcanoes forced magma to the surface which was then cooled to form hard igneous rocks.
Historic plate collisions caused the rocks to be lifted and folded forming mountain ranges (e.g. Scottish highlands and the lake district)
Outline the characteristics of slate and schist.
Schist is formed when slate is pressurised and heated to form a new and harder rock. Schist is harder and much denser than slate. Both are impermeable and very resistant to weathering. However, both can be easily split into thin slabs.
Explain how the uk has been shaped by glacial periods.
Large ice sheets called glaciers shaped the uk land ape by eroding and carving into the landscape to form steep 'u' shaped valleys in upland areas. Glaciers also deposited lots of material when they melted. (e.g. a lot of eastern england is covered in material which was deposited by melting glaciers)
Give three physical processes that alter the landscape
Weathering, erosion and slope processes
Give an example of a lowland landscape
The downs and the wealds are lowland landscapes in the UK
Outline how physical processes have shaped the uk landscapes
Lowland landscapes would have been formed over a number of years through different processes such as erosion and freeze thaw weathering. Many lowland areas would have been formed just after the glacial periods when the colder climate led to more freeze thaw weathering which created the distinct landscapes.
How does forestry alter the landscape?
Forestry has changed the landscape by making it look a lot less natural through planting trees in unnatural straight lines. Forestry is the management of woodland areas, meaning previous woodland areas that have been cut down can be restored and conserved through the plantation of new trees.
How does settlement alter the landscape?
Settlements can alter the landscape if the ground is required to be flattened or risen in order to make suitable space for housing. Settlements has also meant that concrete would have been placed and rivers would have been diverted and straightened in order to prevent flooding.
How does salt weathering break up rock?
Salt weathering breaks up rocks when the sea water gets into the cracks of the rocks. The sea water then evaporates and salt crystals form and expand, putting pressure on the rock. If this process repeats the cracks will widen and the rock will break.
What is hydraulic power erosion?
Waves crash against rock and compress air into the cracks, putting pressure on the rock, and constant pressure will lead to the eventual breakdown of the rock.
What is abrasion?
Eroded particles in the water scrape and rub against rock removing small pieces.
What is attrition?
Eroded particles in the water smash into each other and break into smaller pieces.
What is a concordant coastline?
A concordant coastline only has one rock type on the edge and is made up of a hard rock type.
What is a discordant coastline?
Discordant coastlines are built up of many rock types. Therefore, headland and bays are often formed on these coastlines because the bands of rock are being eroded at different rates.
What are the characteristics of a destructive wave?
Destructive waves have a high height but a short wave length. They have a stronger backwash than swash meaning sediment is removed from the beach. These waves are most common in the winter.
What are the characteristics of a constructive wave?
Constructive waves have a short wave height but longer wave length. They have a stronger swash than backwash meaning sediment is deposited on the beach. These wages are more common in the summer.
Describe how erosion can turn a crack into a cave.
Resistant rocks have weaknesses like cracks. Waves then crash into the cracks, enlarging them. This is mainly through hydraulic power and abrasion. Further erosion will cause a cave to form.
Where and how do spits form?
Spits form at sharp bends in the coastline. Longshore drift transports sediment past the bend and deposits it in the sea. Strong winds can also curve the end of the spit.
Explain how agriculture can have a direct affect on the coast
Farmland has a low economic value meaning it is often left unprotected along the coast. This will change the way the coastline looks as certain areas will erode at faster rates if they are not protected by methods such as sea walls.
How does development affect the coast?
Coastal areas have become a popular place to live and work, meaning lots of infrastructure is built, which leads to the construction of coastal defences (sea walls, slope stabilisation). This means areas with a lot of development are less prone to erosion unlike areas with no development or little development as they are not protected as much.
Give one effect of coastal management on the coastline.
Coastal management can have positive and negative effects on the coastline. It is positive because it obviously protects the coast from erosion however it can also be negative as many people view some methods of management, such as groynes, to be ugly and ruin the beauty of the beach. Hard engineering methods of coastal management are often much more effective than some soft engineering methods however they usually cost more money and can be viewed ugly and unnatural, therefore potentially causing a decrease in the number of tourists that visit beaches.
Why does sea level rise increase the risk of coastal flooding?
Rising sea levels increases the risk of flooding in low lying coastal areas because the sea level rise will cause higher tides, meaning much more frequent flooding. Higher tides can also remove larger amounts of sediment from the beach causing an increased rate of erosion because the surrounding cliffs are not protected.
Give two threats of coastal flooding to people.
People who live in low lying coastal villages may be at threat to flooding meaning they could drown and buildings and homes will be lost.
Coastal industries may be shut down due to a damage in equipment and buildings, e.g. vehicles.
Give two threats of coastal flooding to the environment.
Ecosystems will be destroyed by the flooding and animals may be affected by the high salt levels in the sea water.
Trees and plants may also be destroyed snd uprooted due to the force of the flood.
What is hard engineering?
Hard engineering is the use of man made structures to control the flow of the sea and reduce flooding and erosion. (e.g. groynes and sea walls)
What is soft engineering?
Soft engineering is the use of natural methods and using knowledge of the sea to reduce the effects of flooding and erosion (e.g. slope stabilisation and beach re-nourishment)