Distinctive Landscapes Theory Flashcards
Define landscape
A landscape is all the visible features of an area of land. A natural landscape has more visible physical features. A built landscape has more visible human features.
Define geology
Outline upland areas in the UK
Upland areas are found in the north and west of the UK, consisting of harder rocks (such as slate, granite and some limestones) which resist erosion. Most landscapes are glaciated, with steep gradients.
A harsh (cooler and wetter) climate and thin soil allow rough vegetation to thrive, with some upland areas used for forestry.
Land uses include sheep farming, quarrying and tourism.
Outline lowland areas in the UK
Lowland areas are found in the south and east of the UK, consisting of softer rocks (such as chalk, clay and some sandstones). Most landscapes are flatter with gently rolling hills.
A warmer and drier climate and fertile soils allow much vegetation growth, leading to grassy meadows and deciduous forests.
Land uses include quarrying and tourism, as well as dairy and arable farming. Most urban areas and industries are located in lowland areas.
Define geomorphic processes
Geomorphic processes, such as weathering and erosion, change the shape of the landscape and create landforms.
Describe mechanical weathering
Mechanical weathering is the breakdown of rock without changing its chemical composition.
In the UK, most is freeze-thaw weathering, where temperatures alternate above and below 0°C. Water in cracks expands as it freezes, creating pressure on the rock that is released upon thawing. This process repeats, causing the rocks to break up.
Salt weathering is a similar process caused by the build-up of salt crystals deposited in cracks by waves.
Describe chemical weathering
Chemical weathering is the breakdown of rock by changing its chemical composition.
Carbonation weathering is a type of chemical weathering that happens in warm and wet conditions. Rainwater has carbon dioxide, making it a weak carbonic acid, which reacts with with rock that contains calcium carbonate.
Describe biological weathering
Biological weathering is the breakdown of rocks by living things, such as plant roots breaking down rocks by growing into cracks on their surfaces and pushing them apart.
Describe mass movement
Mass movement is the shifting of rocks and loose material down a slope when the acting force of gravity is greater than the force supporting it, causing coasts to retreat rapidly.
They are more likely to happen when the material is full of water, acting as a lubricant to make the material heavier.
Undercutting of a slope by erosion will increase the chance of mass movement.
Sliding involves material moving in a straight line, leading to a straight slope. Slumping involves material shifting with a rotation, leading to a curved slope.
Describe hydraulic action
In hydraulic action waves crash against rock and compress the air in the cracks, putting pressure on the rock. Repeated compression widens the cracks and breaks off bits of rock.
Describe abrasion
In abrasion, eroded particles in water scrape and rub against rock in the sea bed, cliffs or river channel, removing small pieces and wearing them away. Abrasion accounts for most erosion in rivers.
Describe attrition
In attrition, eroded particles in the water smash into each other, breaking into smaller fragments and rounding off. The further material travels, the more eroded it gets.
Describe solution
As an erosion process
In solution, dissolved carbon dioxide makes river and sea water slightly acidic. The acid reacts chemically with some rocks.
Define transportation
Transportation is the movement of eroded material by rivers and the sea.
Describe traction
In traction, large particles like boulders are pushed along the river bed or sea floor by the force of the water.
Describe saltation
In saltation, pebble-sized particles are bounced along the river bed and sea floor by the force of the water.
Describe suspension
In suspension, small particles like silt and clay are carried along by the water.
Describe solution
As a transportation process
In solution, soluble materials dissolve in the water and are carried along.
Define deposition
Deposition is when material being carried by sea water or river water is dropped, occurring when water carrying sediment loses velocity so that it is no longer moving fast enough to carry so much sediment.
Define constructive waves
Constructive waves deposit more material than they erode, so the swash is more powerful than the backwash.
They are low and long, with a lower frequency of 6-8 waves per minute.
Define destructive waves
Destructive waves erode more material than they deposit, so the swash is less powerful than the backwash.
They are high and short, with a higher frequency of 10-15 waves per minute.
Define headland
A headland is a steeply sided section of rock more resistant to erosion jutting out along a coast with alternating bands of more and less resistant rock.
Define bay
A headland is a gently sloped zone between headlands where rock less resistant to erosion has eroded quickly along a coast with alternating bands of more and less resistant rock.
Define cave
A cave is where cracks in the side of a headland have been enlarged by repeated erosion (mainly hydraulic action and abrasion).
Define arch
An arch is where a cave is deepened until it breaks all the way through the headland.
Define stack
A stack is where the rock supporting an arch is eroded to the point of collapse.
Define stump
A stump is the result of a stack collapsing after being repeatedly undercut at its base.
Define beach
A beach is an area of material between the high and low water marks on a coast, formed by deposition by constructive waves.
Sand beaches are flat and wide and shingle beaches are steep and narrow because larger particles are unaffected by the weak backwash.
