Topic 4 coastal changes and conflict Flashcards
What are the main ways the tectonic activity has shaped the UK’s landscape?
Plate movements
Plate collisions
Active volcanos
What type of rock was formed by magma cooling on the earth’s surface?
Igneous
Charactaeistics of slate:
- Slate is hard and resistant
- formed from heating of shale
- impermeable
- metamorphic rock
(but, because it forms in layers, it can easily be split into thin slabs.)
Characteistics of schist
- very resistant
- impemeable
- metamorphic rock
Schist is made up of bigger crystals and also splits easily into small flakes.
What do slate and schist together commonly form for a landscape?
These rocks often form upland landscapes with waterlogged and acidic soils because of their resistance and impermeability.
Characteristics of chalk:
- harder than clay(medium resistance)
- forms slopes in UK low lands
- cliffs in UK coastline
- permeable (water flows through it)
- younger form of limestone
- sedimentary rock
Charactaeisitics of clay:
- forms wide and flat valleys because it is easily eroded
- sedimentary rock
- not resistant
-lots of water features in clay landscape rock is IMPERMABLE and so water flows to the surface.
Caracteristics of carboniferous limestone:
- heavily affected by carbonation weathering (occurs in joins and causes arches and caves, caverns)
- sedimentary rock
- permeable
- permeable: dry valleys resurgent rivers(i think it means underwater)
-less resistant than igneous rocks but more resistant than other sedimentary rocks.
Characteristics of granite:
- hard and resistant-forms upland landscapes
- unevenly spread joints
- fewer joints-slowed erosion areas can end up sticking out as tors
Moorlands are created on top of granite because it is impermeable.(moorlands-large areas of waterlogged and acidic soil.)
-impermeable
When did an ice sheet most recently cover much of the UK?
About 20,000 years ago.
What did Plate collisons do to the UK landscape?
Mountains were formed by rocks folding and uplifting due to plate collisions
- collisions also generated intense heat and pressure which
- led to the formation of hard metamorphic rocks
(in northern Scotland and Northern Ireland.)
What did active volcanos do to the UK landscape?
- active volcanos erupted magma onto the landscape, cooled and formed igneous rock(granite)
(UK was much closer to a plate margin 520 million years ago.)
What did Plate movements do to the UK landscape?
Remember:345-280 million years ago, the UK was in the tropics.
What rock does volcanos form?
Igneous rock
What rock did plate collisions create?
Metamorphic
How long ago were volcanos erupting magma that is now the land that makes up the UK?
520 million years ago
Which of the following would NOT be found in a chalk landscape?
Cliff
Tor
escarpment (steep slope)
Tor(exposed rock of broken blocks)
Where was britian 345-280 million years ago?
In the tropics
Dueing the tropics where did carbonifeous limestone form?
The warm and shallow seas
Characteristics of granite:
- very resistant
- impermeable
- forms upland landscapes
- lots of unevenly spread joints
- often topped by moorland
What is moorland?
A habitat found in upland areas.
-low growing vegitation and acidic soils
Types of weathering processes:
Mechanical
Chemical
Biological
Examples of slope processes?
Mass movement
- soil creep.
- landslide
What are climatological processes?
The climate affects how physical processes happen.
Eg. Freeze thaw weathering is more likely if tempratures regualy fluctuate above and below 0 degrees C
What are post glacial river processes?
At the end of glacial periods, rivers became much bigger and more powerful as melted ice flowed into them. They eroded the landscape with great force.
When ice melts glacial landforms are left behind
E.g: hanging valleys
- truncated spurs
- glacial troughs
What does erosion proccess mean?
Erosion is the wearing away of rocks as
As a result, rocks being picked up and moved elsewhere.
What are the pysical landscape processes?
Weathering processes Erosion processes Slope proccesses Cimatological processes Post-glacial river processes
What human activities have shaped distinctive landscapes over time?
- agriculture
- settlement
- forestry
What affects where settlements are built?
- water supply
- easy defence
- shelter
- bridging points over rivers
- resource avalibility
The uk is mainly _____ woodland.
Deciduous(leaves fall of every year)
What type of forest are humans replacing decidous woodland so they can manage their timber?
Coniferous(ever green)
Forest has been cleared to make space for ______
Agriculture
What has been installed in some places to make the land dry enough to be farmed?
Drainage ditches
How has settlement changed rivers?
- diversion througg underground channels
- straightening
- embarkments built
What is chemical weathering?
When the chemical composition of rocks changes
When the climate is warm and wet, carbonic dioxide can dissolve in rain to create a ‘carbonic acid’.
The carbonic acid in rainfall hits rocks and dissolves the parts of the rock made of calcium carbonate.
This also breaks down rock.
What is mechanical weathering?
-it is also called physical weathering
physical changes causes rocks to break down(e.g a change lf temprature from day to night)
-the chemical composition of rocks stay the same
- water expands when it freezes.
- water fills cracks,freezes, it expands, putting pressure on the rock.
The water will then melt, but it has put pressure on the rock.
Eventually, this process of freezing and thawing will wear down rock.
What is biological weathering?
-living orginisms break down rock(e.g tree roots by pushing cracks apart
Mass movement: what are slides?
Slides are when material moves down a slope in a straight line.
Mass movement: what are slumps?
a slip plane forms under the cliff. The cliff then slumps down in layers.
Mass movement: what are rockfalls?
When the cliff materials break and crumble down the cliff.
What are the three types of mass movement?
Slides
Slumps
Rockfalls
_____ movement describes the movement of rocks on a hill or cliff.
These movements are caused by weathering, erosion, and g____. Small changes over time can mean that a cliff’s centre of gravity hangs over the sea, instead of over land.
- Mass
2. Gravity
If conditions are warm and what kind of weathering is more likely to take place?
Chemical weathering
What affects the type of coastline?
Type of rock
- joints and faults
- concordant or discordant coastline
What is a discordant coastline?
alternating chunks of hard rock and soft rock at 90o to the coast.
The sea’s waves will hit both hard rock and soft rock when they meet the coast.
-bays are headlines are formed due to hard and soft rock eroding at diffrent rates
What are concordant coastlines?
1 layer of spft rock
Then 1 layer of hard rock.
The sea’s waves will only hit 1 type of rock when they meet the coast.
What is the softest rock?
Talc is the softest
And clay is softer than chalk.
Which of the following rocks is the most resistant to erosion?
Shale
Clay
Limestone
Limestone
Impacts of Climate on Coastal Erosion and Retreat:
Storm frequency
-if storms happen more often there is more destructive waves
This means erosion and weathering will occur more quickly
Impacts of Climate on Coastal Erosion and Retreat:
Seasonality
Temprature changes and a range of temprature can affect erosion and weathering for rocks.
(Freeze-thaw weathering)
Impacts of Climate on Coastal Erosion and Retreat:
Prevailing wind and wind speed.
- The prevailing winds affect where sediment is carried.
- Strong prevailing winds can lead to lots of destructive waves.
(Winds from the Atlantic Ocean hit the south-west of England.)
Impacts of Climate on Coastal Erosion and Retreat:
Rainfall
- at times of heavy rain fall soil can become saturated.
- this causes MASMOVEMENTS to become more likely.
- After heavy storms, chemical weathering may be more likely to happen.
- heavy rainfall usually comes with storms and destructive waves.
What are the 4 features of the UK climate that impact rates of coastal erosion and retreat?
- Prevailing winds
- rainfall
- storm frequency
- seasonality
_______movement becomes more likely during storms because the intense rainfall means that soil is more ________
- Mass
2. Saturated
Describe the prevailing winds on the UK’s south coast.
-south-westerlies
Warm
Bring adlantic storms
What is responsible for most the erosion at the base of a cliff?
Destructive waves.
Wave cut platform:Stage 1:What does destructive waves eroding the base of the cliff form?
A wave-cut notch
Wave cut platform:stage 2:Continued erosion of the _______causes the rock above it to become less and less stable until it _______.
- Wave-cut notch
2. Collapses
What is stage 3 of wave-cut platforms?
Waves wash away the debris from the cliff collapse.
The destructive waves begin to erode the cliff, causing a new wave-cut notch to form.
Wave-cut platforms:Stage 4:
As stages 1-3 happen again and again, more debris falls into the ocean and the cliff retreats.
What is left behind is called a wave-cut platform.
What is left behind after cliffs retreat due to erosion?
Wave cut platform