The Uks Evolving Physical Landscape Flashcards
What is igneous rock
And examples
A rock formed through the cooling of and solidification of magma
Diorite
Granite
Pegmatite
Sedimentary rock
And examples
Formed when layers of sediment compact together. until the become solid rock
Carboniferous limestone and chalk
Clay and shales
Metamorphic rock
And examples
Rocks are formed when igenous or sedimentary rocks are changed due to pressure and heat. Becoming harder and more compact
Slate
Schist
How do volcanoes effect the landscape
Active volcanoes forced magma to the surface . This magma cooled and solidified to form igneous rock
How did glaciers effect the landscaep
Plucking
Freeze thaw
Abrasion
Where is Snowdonia located
Upland
Describe lilyn idwal
A corrie hollowed out by glaciers
Freeze thaw weathering occurs on the steep back walls breakingup rock and forming scree
Why do streams and gullies occur around snowdonia
Land of impermeable rock meaning water can only erode the sides of the channel
Where is the weald
Lowland
Why are dry valleys found in lowland landscapes
Valleys with no visble stream. Formed during glacial periods where the colder climate allowed for more freeze thaw weathering and glacial slow melt provided more water than the warmer climates we had today
How have humans changed the landscape
Agriculture
Clearing vegatation
Sheep grazing
Hedgerows and walls
Forestry
Replantation is unnatrual
Harvesting of descidous woodland
Settlements Bridging points over rivers Infastrcture Concreted surfaces affecting drainage patterns Rivers modified with embankments
Mechanical weathering
Salt weathering through repeated expansion and contraction of crystals
Chemical weathering
Changing chemical composition of surface
Explain mass movement
Shifting of rocks and loose materials down a slope as the force holding them up is weaker than gravity. Water can help loosen the mud and material
What aee the three types or mass movement
Slides
Slumps
Rockfallw
What three erosion processes effect the coast
Abrasion
Attrition
Hydraulic action
Climate impacts on costal retreat
Milde weather causes salt weathering
Storms are more frequent stronger winds can cause destructive waves to occur more
Increased rainfall can increase mass movement
Development of a wave cut platform
Wave causes erosion at bottom of cliff
Forms a wave cut notch
Rocks above become unstable and collapse
Collapsed material is mashed away
Process continues resulting in cliff retreat
Platform is left behind
Formation of headlands and bays
Form with alternating bands of hard and soft rock
Less resistant rock erode first forming a bay
Resistant rock is eroded slower and left jutting forming a headland
Formation of cave to arch to stacks
Waves crash into headland enlarging cracks due to repeated erosion causing a cave to form
Erosion deepens cave until it breaks the other side forming an arch
Erosion wears way at arch until it collapses eventually leaving isolated rock called stacks
Explain longshore drift
Waves follow direction of prevailing winds usually hitting at an oblique angle
Swash carries sediment up the beach
Backwash pulls it back at a right angle
Over time material zig zags across the beach
Formation of a spit
Spits form at a sharp bend
LSD transports sand and shingle into the sea
Strong winds cause waves to curve and therefore cause the curve of the spit
The sheltered area behined the spit is protected from waves
Mud accumulates there and allows plants to grow there
Formation of a BAR
A bar is formed when a spit is joined by a headland
The water behind the bar is cutoff and becomes a lagoon
Human activities on coast
Agriculture
Vegetation can stabilise cliffs
Exposure of soil when vegatation is grazed
Reduction or natural flood barriers (marshland)
Development High cost areas Low cost areas Hold the line Retreat the line
Industry
Gravel extraction
Removal of salt marshs (natrual flood barriers)
Holderness
Contains high value areas . Over 14000 people live in the towns near by . Town such as hornsea.
Defences such as groynes
Problems of costal defences
Groynes prevent erosion in high value areas however places such as great mowden where caravan parks and farms are at risk as there is sediment starvation allowing for quicker erosion
Spurn head also at risk
How does climate increase costal flooding
Storm frequency
Rising sea levels
Sea walls
Made or hard concrete . Reflects the energy of the waves back into the sea
It prevents erosion and is a barrier to stop flood
Creates a strong backwash , they are expensive to build and maintain
Groynes
Wooden or stone fences that trap sediment which would be transported via LSD
Creates wider and more attractive beaches and are fairly cheap
They starve beaches later down the coast of sediment . Making them narrower
Wood rots
Beach replenishment
Sand and shingle is added to the upper parts of beaches
Creates wider beaches which slows waves. Gives protection for flood and erosion
Taking material can kill organisms . Its very expensive as the process must be repeated
Slope stabilisation
Slopes are reinforced with metal netting and nails
Prevents mass movement making coasts safer to travel on
Slope stabilisation is hard to install and is expensive
Strategic realignment
Removing an existing flood defenses and allow the land behind it to flood
Controls where floods can occur . Letting of the pressure constantly reduces the likelihood of a huge flood in high cost areas
Intergrated costal management zone
A scheme that takes everyones opinions into account and tries to find the outcome of every-bodies interests
