Coasts Falscards Flashcards

1
Q

Igenous rock

A

Igneous rocks are formed when molten rock from the mantle cools down and hardens. Rocks form crystals as it cools. They are usually hard e.g granite

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2
Q

Sedimentary rock

A

Layers of sediment are compacted together until solid. Limestone and chalk formed from tiny shells and skeletons of sea creatures

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3
Q

Metamorphic

A

Formed when other rocks are changed by heat wnd pressure. New rock becomes harder and more compacted

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4
Q

Granite

A

Formed from magma cooled underground,resistant
-lots of joints which aren’t evenly spread so more joints more erosion.
-impermeable which creates moorlands

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5
Q

Limestone

A

Formed from tiny shells and skeletons of sea creatures. Very resistant and permeable and is resistant

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6
Q

Clay

A

Formed from muds deposited by rivers. Soft and crumbly. Weak

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7
Q

Chalk

A

A younger form of limestone. Medium resistance but stronger than clays
-forms enscarpmentd and cliffs at coasts
-permeable

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8
Q

Slates

A

Formed by heated muds. Very resitant and hard to weathering
-forms in layers creating weak planes in rocks

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9
Q

Formation of healand and bays

A

-sea attacks coast with alternating bands of hard and soft rock
- soft rick erodes more quickly than hard rock
-leaves land our called headland
- Areas with soft rock has eroded away are called bays

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10
Q

Formation of a spit

A

-Longshore drift moves sediment along coastline
-sudden change in coastline is required to occur
-behind headland a sheltered area is present where lower energy waves occur
- heaviest sediment dropped first and after smaller sediment is dropped
- ‘re-curved cause by 2nd wind’
- spit will not reafh to other side due to deep water and currents

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11
Q

How do arch,stump,stack form

A

-waves crash into headlands and enlarge cracks-abrasion and hydraulic action
-repeated erosion enlarges the crack to form cave
- continued erosion deepens crack and causes a arch
- erosion causes supporting arch to fall
-forms a stack

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12
Q

Longshore drift

A

Waves approach the sea at an angle, swash pushes material up the
beach at the same angle as the prevailing wind. Backwash carries the sediment back
dow

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13
Q

Traction,saltation,suspension and solution

A

Traction– large boulders are rolled along the sea
Saltation—smaller stones are bounced along the sea floor.
Suspension—sand and small particles are carried along in the flow.
Solution—some minerals are dissolved in seawater.

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14
Q

Constructive waves and destructive waves

A

Constructive waves— Have a
strong swash and weak
backwash, small waves under 1m
high. Encourage deposition.
Destructive waves—Strong
backwash, weak swash, taller
than 1m. Encourage erosion.

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15
Q

Concordant and discordsnt coastlines

A

Discordant-perpendicular, headlands and bays formed, coastal erosion and deposition
Concordsnt-parallel, coes, coastal erosion and landforms

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16
Q

Hudraulic action,abrasion,attrition in waves

A

Hydraulic action-waves crash against rocks and compress air into cracks. Puts pressure on rocks. Repeated action causes cracks to widen and break off
Abrasion-eroded particled in water scrape and rub ahainst rock,removing small pieces
Attrition-eroded particles in rock smash into each other and break into smaller fragments.

17
Q

Mass movement, slumping and sliding

A

Mass movement—the
downhill movement of
material under the
influence of gravity.
There are different types
that depend on the
material involved, how
saturated the material is
and the nature of
movement. E.g.
Sliding - loosened rocks
and soil suddenly tumble
down the slope.
Slumping—happens when
rock is saturated with
water and slides down a
curved slip plain.

18
Q

Tectonic activity in the uk

A

-520 million years ago land that now makes up Uk used to be much closer to plat boundary than it is now. Active volcanoes formed magma through earth’s crust which cooled to form igenous rock.

-plate collisions caused rocks to be folded and uplifted forming mountains. Many of these areas remains as uplands
-the intense heat and pressure caused by plate collisions formed metamorphic rock in scotland ireland

-plate movements years ago mean that Britain was in tropics and higher sea levels meant it was partly underwater-canfiberous limestone formed in dhallow seas. Can be seen in uplands of peak district
-youngest rocks are chalk and clay in southern england.formed in shallow seas and swamps. Chalk and clay are softer rock ehich are more easily eroded-form low landscapes

19
Q

Distinct land scapes-lake district uplands

A

Igeneous basalt rock from surface eruptions and granite iepgenous eruptuons below surface
-large volcanoes erupted at lake district 450-300 million years ago
-glacial processes 12000 years ago the uplands were under 300m of ice which eroded corries. Eroded huge areas to creat u-shaped valleys. Steepsides,flat bottom and hanging valley
-land is angular p u-shaped valleys and v-shaped valleys with steep mountains
-freeze-that weathering occured
-rockfalls and landslides occur
-misfit rivers are formed
-cold in winter and warm jn summer-rainsall year round

20
Q

Distinct landscape UK-weald (lowland)

A

-sedimentary rock which are softer-green sand and chalk which are harder
-dry valleys,chalk froze making it impermeablr so when snow melted couldn’t infiltratr and ran over top causing valleys
-flat landscape with hills and v-shaped valleys. Shallow,floodplains, gentle landscape and vegetation
-biologicsl weathering and chemical weathering
-soil creep-soils such as sandstones and clay can absorb moisture and become saturated causing movement down slope
-floodplains formed
-wet and heavy rain. Warm in summer and cold in winter

21
Q

Distinctive landscapes-upland

A

Settlement-farms-dispersed and isolated,farms and villages,small communities
Building material-local bricks and slate,stone
Field boundaries-follow shape of land,stine walls which are well structured, long lasting land
Farming-sheep farming and hay in winter valleys
Econimic activity-primary-agriculture,windmills

22
Q

How have humans chnaged landscape-agriculture,forestry, settlement

A

Agriculture- people cleared land of forest to make space for farming
-hedgerows and walls to mar out fields
-differet farming-arable so flat kand with good soul for crops-dairy for warm and wet areas for dairy farming-sheep fatmint takes place in uplands which has led to a lack of tress.

Forestry-management of areas of woodland used for timber,conservation
-coniferous forests been planted for timber which are olanted in straight lunes so forests don’t look natural
-devidous woodland is being replanted in simebareas to make landscape more natural

Settlement- land was concreted over for roads and buildings which affected drainage patterns
-some rivers diverted through underground channels
-some river channels straightened or had embankments built to prevent flooding
-most of big citis are ports and industrial areas

23
Q

Mechanical,chemical and bilogical weathering

A

Mechanical weathering-freeze-that weathering where water gets into cracks. Water freezes causing cracks to expand na d rocks fall off
Chemical weathering-seawter and rainwater have carbon dioxide dissolved which makes them weak carbonic acids. Carbonic acid reacts with rock that contains calcium carbonate.
Biological weathering-plants break down rocks by growing into cracks on their surface pushing them apart

24
Q

Wave cut notch’s and platform formation

A

-waves cause most erosion at foot of a cliff
-forms a wave-cut notch which is enlarged as erosion continued
-rock above notch becomes unstable and collapses
-collapsed material washed away and new wave-cut notch starts to form
-repeated collapsing causes cliff retreat

25
Q

Transportation

A

-waves followndirevtion of prevailing winds which hit coast at an oblique angle
-swash carries materialbup beach in same direction as waves
-backwash carrues material down beach at right angle back to sea

26
Q

Deposition

A

Deposition is when material carried by seawater is deposited by contructive waves and forms landscapes such as:beaches,spits and bars

27
Q

Solution,suspension,stravtion,slatation

A

Solution-dissolved chemicals often deprived from limestone or chalk
Suspension-particles carried within water
Saltation- a hopping lr bouncing motion ofnparticles too heavy to be suspended
Traction-large pebbles rolled along sea floor

28
Q

Direct and indirect effects in coast

A

Agriculture-low economic balue so unprotected so has direct effect on coastal kandsvaoe as sea can erode cliffs and shape land
-changing farmland can cause instability in cliffs
-land is sometimes reclaimed and drained for sgriculturslnuse. Draining directly affects coast as reduces natural flood barrier that marshaland provide

Develolopment-coastal areabpopulatpr for work and tomlive so have development
-lots of settlement have more coastal defences than other areas as people want to protect their homes and businesses so has a positive direvt affect on coastline as land is better protected against erosion
-however an indirect affect is change in transportation and deposition of material along coast as it can cause beaches to be narrower as restricts sediment supply to beached. Narrow beaches dont protect coastline well so more vunerable to erosion.

Industry-coastal quarries expose large rocks making them more vunerable to chemical weathering and erosion
-gravel extracted from beaches which has removed material from coast and increased risk of erosion as less material to protect cliff

Coastal management-protecting coastal landscaoe from impacts of erosion
-some management strategies alter sediment movement, which reduces amount of protective beach material further along coast increasing erosion
-coastal defences reducing erosion. Direct effect on coast as prevents landscape from changing

29
Q

Hold the line,advance the line,strategic retreat,no active intervention

A

Hold the Line– use sea defences to stop erosion
and so the coast stays where it is - expensive
Advance the Line– By building new defences on the
seaward side of the original defences - very
expensive
Strategic Retreat/Realignment– Gradually let low
value areas of the shoreline to erode backwards to
help protect high value areas. Compensation is
given.
No Active Intervention– Where there is no
investment in coastal defences or operations.

30
Q

Explain how physical factors have caused a chnage in holderness coastline

A

-cliffs made from boulder clay which is easily eroded. Likely to slump when wet causing cliff to collapse
-becahes are narrow, which means they don’t get enoigh protection for cliffs from sea erosionsl power
-faces prevailing winds which bring waves from north eadt from norwegian sea. Waves increasenpower over long distance so coast is battered by highly erosive waves

31
Q

Bridgelington,mappleton,great cawden, easington

A

Brdiglington:large population of 30k,tousim jobs,fishing income so groynes and seawall protect
Mappleton: approx 50nproperties,subejct to intense erosion at 2m per year and 50m road so rock groynes and armour for protection
Great cawden: farmland,caravan parks auffer due to no coastal management
Easington: gas terminal in uk accountd 25% of british gas supply so sea wall and rock armour to protect

32
Q

Positive of coastal defences in holderness coastline

A

Over 11km protected by hard engineering:
-protects towns and gillages like hornsea,withernsea and mappleton
-important infrastructures like roads
-gas terminal easington 25% of uk gas

-groynes built at mappleton
-gorynes and sea wall at hornsea and withernsea

33
Q

Negative on coastal defences on holderness coastline

A

-groynes protect local aresd but cause narrow beaches to form further down coastline. Increases erosion so risk of caravn patkd and farms of falling into sea
-reducing amount of materual thats eroded and transported south increase risk of flooding
-less new material added on coast causes coastal retreat

34
Q

Climate change increasing risk of coastal flooding

A

Rising sea levels pose a threat ti low lying and coastal areas which could cause higher tifed ghat would flood coastal aread more frequently. Could also remove large amounts of material from beaches so increased erosion on cliffs

-storms becoming more frequent
-give sea more erosional power so areas with soft rock will be more quickly eroded

35
Q

Hard engineering-sea walls what is it?benefits?costs?

A

A wall made out of hard material like concrete that reflects waves back into sea.
-prevents erosion of coasts and barrier to prevent flooding
-creates strong backwash,which erodes under wall. Sea walls are expensive to build and maintain

36
Q

Hard engineering-groynes what is it? Benefits?costs?

A

Wooden or stone fences that are buily at right angles to coast. Trap material transported by longshore drift
-creater wider beaches which slow waves. This gives greater protection from flooding and erosion. Fairly cheap
-starve beaches further down coast making them narrower. Really expensive

37
Q

Soft engineering-Beach nourishment ehat is it? Benegits?costs?

A

Adding sediment to beach builds up beach height which absorbs wave energy and orevents waves breaking at cliffs
-relatively cheap,looks matural and attrcats tourism
-replacement of sediment often needed,winter storms transport material away

38
Q

Soft engineering-Slope stabilisation what is it?benefits?problems and costs?

A

Vegetation is olanted by planting grasses and shrubs so roots can stabilise soil. Drainage pipes arebplaced which reduces water pressure and prevents saturation. Together,reduces mass movement slumping
-dont interfere with coastal process of LSD transport,reduces mass movement, keeps cliff in place and safer for beach users
-up to 1 mill for slope stabalisation. Difficult to install and beach may be closed for long time