Presentation on theme: "NATIONAL GEOGRAPHY GLACIATION REVISION"— Presentation transcript:
1 NATIONAL GEOGRAPHY GLACIATION REVISION
ST. ANDREW’S HIGH SCHOOLNATIONAL GEOGRAPHY GLACIATION REVISION
2 Upland Glaciated Landscapes
3 By the end of this Unit of work you should be able to understand that:
Glaciers are made of ice and they flow very slowly.Glaciers erode, transport and deposit material.Glaciers create lots of different landforms.Glacial landforms can be recognised on maps.Glaciated upland landscapes can be used in a variety of ways.Glaciated upland landscapes need to be managed for the future.Weather affects glaciated upland areas in certain ways.
4 Location of Glaciated Landscapes
5 Freeze thaw Action or Frost shattering
It is most effective where the temperature fluctuates around 0°C, eg on north-facing high altitude slopes.
6 Freeze thaw action causes the rock to shatter.
Sharp, angular pieces of rock are formed called scree.The broken rock falls and builds up at the base of an area of exposed rock. To form a scree slope.Generally the larger material builds up at the base, while finer grains are washed into spaces.The angle of a scree slope is degrees
7 PluckingPlucking is when rocks and stones become frozen to the base of the glacier and are plucked from the ground as the glacier moves.
8 These lines on rocks are called striations
AbrasionThese lines on rocks are called striationsDirection ice movementRocks scrape against the bedrockBedrock is scratched and polishedRocks and stones, picked up by the glacier are rubbed against the bedrock at the bottom and sides of the glacier.The rock is scratched, polished, smoothed and eventually worn away by the scouring action.The pieces of rock in the ice also become smaller through this rubbing action.
9 Snow collects in hollows and compacts to ice.
Ice moves under gravity and its own weight, lubricated by meltwater-rotational sliding.Ice erodes more at the base and back of the hollow to form a raised lip at the frontAbrasion deepens the corrie.Plucking and freeze thaw action steepens the back and sides.A Corrie lochan (tarn) may fill hollow.
10 Steep backwallScreetarnDeep armchair hollow
11 Overdeepened hollow steep back wall
Formation of a Corriefreeze thaw actionsteep backwallOverdeepened hollowRotational sliding/slipscreepluckingmoraineabrasionliptarnLabel it to show:-Overdeepened hollow steep back wallrotational sliding/slip scree moraineplucking abrasion freeze thawtarn lip
12 Formation of a Pyramidal Peak or Horn
MatterhornWhen three ormore corries erodebackwards a sharppointed pyramidshape is created.This is called aPyramidalPeak or Horn.
13 Formation of a Pyramidal Peak or Horn
Three or more corries form around a peak.Where corrie sidewalls meet they form an arête (knife edge)The corrie erode into the peak.Arêtes meet to form a horn (pyramidal peak).
14 Recap a) 1. Name the glacial erosion features shown in the diagram. b)
2. Choose one of the following and with the aid of an annotated diagram explain its formation:corriearêtePyramidal peaktarn
15 Characteristics of a Glacial U-Shaped Valley
steep valley sidesmisfit streamhanging valleyBetween truncated spurs are hanging valleys which have not been eroded as deeply as the main valley.The river that flows through the valley after the ice age is described as a misfit stream.Interlocking spurs are truncated as the glacier cuts straight through the landscape.wide and flat valley floortruncated spurs
16 Truncated SpursTruncated spurs are rounded areas of land which have been cut off. They are often rounded at the top but steep at the bottom. They are formed when glaciers move through the main valley and cut off spurs.
17 How and why do these valleys differ?
river valleyglaciated valleyUnlike a river, a glacier fills the entire valley and so has much more power to erode.It does not have to wind around interlocking spurs and can widen, deepen and straighten its valley.
18 V Shaped river valleyBefore GlaciationInterlocking spursDuring GlaciationCorrie glaciers flow into main valleyMain valley glacierSmaller tributary valleyAfterGlaciationValley overdeepened, widened, straightenedWide flat bottom,steep sides
19 Hanging valley clipA hanging valley is a smaller side tributary valley left 'hanging' above the main u-shaped valley.A waterfall can often be seen. During glaciation the smaller side valley contains less ice than the main glacial valley, which is why it is not as deeply eroded.
20 Misfit rivers meander flow through the flat, wide U-shaped floor
Misfit rivers meander flow through the flat, wide U-shaped floor. They look too small for the size of the valley. They did not erode the valley, as they formed in the valley after glaciation had carved out the U-shaped valley.
21 Name the features shown in the diagram below: corrie, pyramidal peak , hanging valley, truncated spur, alluvial fan, tarn, arête, ribbon lake , misfit stream, U shaped
22 Fieldsketch of Cwm Idwal looking south-west
steep backwallshattered rock/screetarnfence
23 Learning Intention To understand what upland Glaciated Erosion Features look like on O.S Maps.
Success Criteria To be able to use a variety of OS Maps to identify upland glaciated features.
24 Corrie and Corrie Loch on a Map
Notice the circular contour lines to represent the circular shape of the corrie. They are close together to show the steepness of the back and side walls. The corrie loch is represented by an area of blue to show water.
25 Tarns or lochans can be found within the horseshoe shaped corrie
Names also help such as corrie,cirque,cwm,coireArmchair shaped hollow Look for Horseshoe shaped contours
26 Arete on an O.S.MapAn arête is found between two corries the land is high and the symbol for bare rock appearscorrieBare rockCorrie with a tarn
27 Pyramidal Peak on an O.S.Map
CorriesLook for a spot height or a triangulation station with 3 or more corries surrounding it.
28 U-shaped Valley on a Map
Notice that the lines are very close together at each side to represent the steep sided valley walls and there are no contour lines in the middle because the valley floor is flat.
29 U-shaped valley and Ribbon lake on an O.S.Map
Whiteness on map due to flat valley floorRibbon LakeSteep Valley sides close contours
30 U-shaped valley with misfit stream that looks too small for the size of the valley
Scree broken rock – look for black dotsTruncated Spurs look for the black rock outcrop pattern running parallel along the sides of the U-Shaped valley
31 Task 1 identify the features labelled below:
32 You may see a lot of tourist symbols, why might that be?
Glaciated areas are very attractive to tourists. They provide:Beautiful sceneryRecreational (sport) facilitiesSkiingHill walkingRock ClimbingMountain bikingWatersportsPicnic Site: remember tourist symbols are blue.
33 Examination questionList three pieces of map evidence to show that this area was glaciated.Map evidence:Circular lake with steep backwall (contours close together) – a corrieDotted black lines suggest scree-like features – evidence of steep slopes and frost shattering – could be present day but steepness influenced by glaciationTightly-packed contours creating circular hollows – several corrie type features cutting back-to-back to create steep ridges that may be arêtesOpportunity to raise map skills techniques here – on an OS map students could quote grid references, heights and named examples
34 Glaciation Map workCan you identify a U-shaped valley by giving a grid reference?Can you identify a Corrie and Corrie loch by giving a grid reference?Can you identify an arête and pyramidal peak?
35 Land Use in Loch Lomond clip Learning Intention- To understand how the different glacial features are used. Success Criteria- To explain the advantages and disadvantages of different landuses.
36 National Parks in the UK
A National Park is a large area of countryside protected by rules and laws. National parks are found in beautiful and special areas including mountains, moorlands and coastal areas.
37 Scottish National Park Aims
to conserve and enhance the natural and cultural heritage of the area,to promote sustainable use of the natural resources of the area,to promote understanding and enjoyment (including enjoyment in the form of recreation) of the special qualities of the area by the public, andto promote sustainable economic and social development of the area’s communities
38 Can you spot 8 landuses in this upland glaciated landscape.
39 Sheep Farming
40 Hanging valleyHydro Electric PowerLoch Sloy
41 ReservoirsGlen FinglasU-shaped Valleys
44 TourismLearning Intention -To understand the reasons for large numbers of tourists visiting Loch Lomond. Success Criteria –To sort impacts of tourism into benefits and problems.
45 THE A82 ROAD AS IT SKIRTS THE EDGE OF LOCH LOMOND
Benefits of Tourism
46 Problems of Tourism
47 Land Use ConflictsLearning Intentions- Understand the pressure on the landscape from a variety of usersTo be able to describe land use conflicts in a National Park.
48 Conflicts Quarrying vs. Tourists/ Famers/NP
-Dust from blasting, lands on farmers fields harming cropsTraffic congestion on local roads due to slow moving trucksNoise of blasting ruins peaceful atmosphere of National Park and dust and waste can enter riversDecline in number of touristsBlasting is noisy and creates dust and air pollutionIt is not sustainable and uses non renewable resourcesAnimal habitats ruined, breeding grounds disrupted and farm animals frightened.
49 Leisure activities e.g. paint balling or climbing walls
SolutionsLeisure activities e.g. paint balling or climbing wallsQuarry signs to show times/days of blastingCover trucks before they leave the siteHose off trucks to wash off excess dust or transport rock by railwayHide disused quarries with treesFill quarries with water for fishing/nature reserveSolutionsLeisure activities e.g. paint balling or climbing wallsQuarry signs to show times/days of blastingCover trucks before they leave the siteHose off trucks to wash off excess dust or transport rock by railwayHide disused quarries with treesFill quarries with water for fishing/nature reserve
50 Tourists vs localSecond homes force up house prices meaning some locals can’t afford housesJobs are seasonalIncrease in traffic on local roads; pollution and journey timesTourism raises prices in local shops so villagers can’t afford higher pricesNew developments spoil the view e.g caravan sites, hotels
51 SolutionsLimit number of second homes in areaTighter regulations for planning permission and new developmentsEncourage use of facilities all year round e.g. hotels for conventions, field trips,special offersDiversification e.g farmers can supplement their income though other activities such as a farm shop, quad bikingPark and ride facilities from major cities
52 Tourists vs Farmers/N.P
Tourists drop litter which animals can choke onTourists leave gates open causing animals to escapeLitter causes visual pollutionFootpath erosion caused by tourists not sticking to the pathNoise and congestion problems
53 SolutionsNational park rangers educate tourists about the Park and can issue on the spot finesMore signs to encourage people to take litter homeSwing shut gatesStone lined paths or fences put up
54 Role of Organisations that protect Loch Lomond
Learning Intention : To understand the role of different organisations which help to protect upland glaciated areas.Success Criteria;To recall different management strategies used to help protect upland glaciated areas.RSPB- Inversnaid RSPB nature reserve has been set up to increase the amount of native woodland for the benefit of breeding birds, such as pied flycatchers and wood warblers.
55 The Great Trossachs Forest project is a collaboration made up of Forestry Commission Scotland (FCS), RSPB Scotland, Woodland Trust Scotland (WTS) and multi-national company, BP.The main aims of The Great Trossachs Forest project is for sustainable land management and use. Tree planting, natural woodland regeneration to try and increase the wildlife.
56 Scottish Natural Heritage is the government's adviser on all aspects of nature and landscape across Scotland. They aim to help everyone understand, value and enjoy Scotland's nature now and in the futureThe John Muir Trust is a UK conservation charity dedicated to protecting wild places. It also runs an environmental award scheme encouraging awareness and responsibility for the natural environment, in a spirit of fun, adventure and exploration.
57 SEPA manages the water environment(quality,pollution levels). Examples of work:Managing recreation on and around water bodies through Byelaws on Loch Lomond and codes of conduct (speed restrictions, laws on boats/behaviour)EducationWorking with communities/partners to protect and enhance the water environment.Work with user groups fishermen, commercial boat users, tourists.
Landscapes of glacial erosion on an OS map
Landscapes of glacial erosion are found in the North and West of Britain including the North-west Highlands, the Cairngorms, the Lake District (Cumbria) and Snowdonia (part of the Welsh Cambrian Mountains). You should know how to describe and explain features of glacial erosion and be able to recognise them on an OS map.
A corrie is an armchair shaped hollow, high on a mountain with steep back and side walls. After glaciation, the hollow may be filled by a small lake or tarn.
Snow gathers in mountain hollows, especially north facing hollows, where there is more shade. This snow builds up and compacts to ice (neve). The action of gravity means the ice moves down the hill. As it goes, it sticks to back walls and plucks rock from the surface. Rocks on the backwalls are loosened by freeze-thaw action. A gap between the wall and the ice develops, called a bergschrund. Ice moving with loose rock acts like sandpaper and deepens the hollow by abrasion. Most erosion is where the weight of the ice is the heaviest. Stones frozen in the base of the ice grind or abrade the corrie base, deepening it. Ice in a corrie has a rotational movement which means that the front of the corrie is less eroded, and a lip forms. The glacier retreats and melts, often leaving a Tarn/glacial lake in the base of the corrie.
An arête is a narrow knife-edged ridge where two corries have eroded back to back. That is, when the back walls of a corrie have been eroded back so far that only a narrow ridge separates them.
Pyramidal peaks or horns have a sharp summit and steep slopes on at least three sides. A pyramidal peak may form where three or more corries erode back so far that they produce aretes with a pyramidal peak in between.
U-shaped valleys have steep sides and a wide, flat floor. They are usually straight and deep.
U-shaped valleys are formed in river valleys which, during the ice age, have been filled by a large glacier. These glaciers have deepened, straightened and widened the valley by plucking and abrasion.
Hanging valleys and truncated spurs
A hanging valley is a smaller side valley left 'hanging' above the main u-shaped valley. A waterfall can often be seen. During glaciation the smaller side valley contains less ice than the main glacial valley, which is why it is not as deeply eroded.
Truncated spurs are rounded areas of land which have been cut off. They are often rounded at the top but steep at the bottom. They are formed when glaciers move through the main valley and cut off spurs.
Ribbon lakes and misfit rivers
A ribbon lake is a large, narrow lake occupying a u-shaped valley. It forms in a hollow when a glacier has more deeply eroded less resistant rock or it may fill up a valley behind a wall of moraine across the valley.
Misfit rivers meander through the flat, wide U-shaped floor. They did not erode the valley, as they formed in the valley after glaciation had carved out the U-shaped valley.
Features of glacial erosion are also covered in Standard Grade Bitesize: Glaciation.