Distinctive Landscapes Flashcards
Define a landscape
All the visible features of a land
What is a natural landscape?
When the majority of the landscape is made up of natural/physical elements
What is a physical landscape?
When there are more human elements than physical elements
What are some of the highest places in the UK?
Ben Nevis, Scotland
Slieve Donard, N.Ireland
Scafell Pike,Cumbria
Snowdon, Wales
What is the lowest place in the UK?
Holme Fen, Cambridgehsire
Where are some glaciated areas in the UK?
North West Highlands, Snowdonia, Lake District, Loch Lomond
How does geology influence landforms above the surface?
- Igneous: volcanic, high mountains e.g. granite
- Sedimentary: layers of compacted organisms and sediment e.g. limestone
- Metamorphic: action of heat and pressure e.g. slate
What is mechanical weathering?
Breakdown of rock by changing chemical composition. Main type = freeze thaw
What is chemical weathering?
Breakdown of rock by changing chemical composition.
What is biological weathering?
When living things break down rocks by growing into cracks and pushing them apart.
What is mass movement?
When material suddenly falls down a slope causing coasts to retreat. Gravity > force supporting material
What is sliding?
Material shifts in a straight line by gravity down a slope.
What is slumping?
Material shifts with rotation by gravity down a slope.
What is abrasion?
Eroded particles in the water scrape against rock in the sea bed, cliffs or river channel, removing small pieces and wearing them away.
What is attrition?
Eroded particles in the water smash into each other and break into smaller fragments rounding off the edges.
What is hydraulic action?
Along coasts waves crash against rock and compress the air in the crack which puts pressure on the rock. Repeated compression widens the cracks and breaks bits off.
What happens in a solution (erosion)?
Dissolved CO2 makes sea water acidic. The acid reacts chemically with some rocks.
What is deposition?
When material being carried by sea water or a river is dropped. It occurs when water carrying the sediment loses velocity so that it isn’t moving fast enough to carry so much sediment.
What is traction?
Large particles like boulders are pushed along the river bed/sea floor by force of water.
What is saltation?
Pebble-sized particles bounce along the river bed/sea floor by force of water.
What is suspension?
Small particles like silt/clay are carried along by water.
What is solution?
Soluble materials dissolve in the water and are carried along by water.
Describe the process of longshore drift
Waves follow the direction of the prevailing wind. Swash carries material up the beach, in same direction of waves . The backwash carries material down the beach at right angles towards the sea. Over time, material zigzags along the coast
How are headlands and bays formed?
When alternating bands of soft and hard rock. Soft rock erodes quickly forming a bay - bays have gentle slopes. The hard rock erodes slowly and is left jutting out.
How does a cave form?
Waves crash into headlands and enlarge the cracks- mainly by hydraulic power and abrasion. Repeated erosion cause cave to form.
How does an arch form?
Further continued erosion deepens the cave until it breaks through the headland forming an arch.
How does a stack form?
Roof of arch becomes too heavy so it collapses forming a stack that is a rock separate from the headland.
How does a stump form?
Stack is undercut and collapses leaving a stump.
How do beaches form?
Formed by constructive waves depositing material. Sand particles are small and the weak backwash can move them back down the beach, creating a long, gentle slope.
Shingle particles are large and the weak backwash can’t move them back down the beach, creating the particles to build up and a steep slope.
How do spits form?
longshore drift transports sand and shingle past the bend and deposits it in the sea. Strong prevailing winds and waves curve the end of spit. The sheltered area behind the spit is protected from the waves allowing plants to grow as material builds up there. Over time sheltered area can become salt marsh.
How do v-shaped valleys form
In upper course of a river, fast-flowing water following heavy rain and high turbulence causes loose particles to be transported by the river and scraped along the river bed. Causing downwards erosion of the river channel by abrasion. The valley sides are exposed to weathering. So the weathered material that falls down the valley causes further erosion by abrasion. The river doesn’t have enough energy to erode sideways so vertical erosion is dominant and deepens the valley to a V.
How does a waterfall and then a gorge form?
Forms when a river flows over an area of hard rock followed by soft rock. The softer rock erodes more and as the water goes over it, it erodes more. A steep drop is created. The hard rock is eventually undercut by erosion and becomes unsupported. Then collapses. Collapsed rocks drop at the foot of the waterfall where they erode softer rock by abrasion creating a plunge pool.
Over time more undercutting causes more collapses. The waterfall will retreat (move back up the channel) leaving behind a steep-sided gorge.
How do meanders form?
The current flows faster on the outside bend because the river channel is deeper. So more erosion takes place on the outside bend forming river cliffs. The current flows slower on the inside bend because the river channel is shallower. So eroded material is deposited on the inside forming slip-off slopes.
What are floodplains and how do they form?
It is the wide valley floor on either side of a river that occasionally gets flooded. When a river floods into the floodplain, the water slows down and deposits the eroded material that it’s transporting. This builds up the floodplain making it higher.
How do ox-bow lakes form?
Erosion causes the outside bends to get closer. There is a small bit of land left between the bends which the river breaks through eventually. River flows along the shortest course and deposition eventually cuts off meander.
How do levees form?
Natural embankments along the edges of a river channel. During a flood eroded material is deposited over the floodplain. Heaviest material deposited closes to the river channel because it gets dropped first when the river slows down. Over time, deposited material builds up creating levees.
