theparkeracademy.e-act.org.uk€¦ · web view2021. 6. 5. · ‘fjord’ is a norwegian word....
TRANSCRIPT
Unit title/key question: Glaciation
Component 1: What are glaciers?
The significance and important of ice and glaciers is not likely to have occurred to pupils before, perhaps unless they have been skiing.
Pupils will begin this unit by watching a documentary ‘The Power of Ice’. This will provide them with an overview of the role of ice on Earth and also a mental image of ice covered landscapes when they are referred to in subsequent lessons.
Pupils should have a securing understanding of the following key terms:
Glacier – A large mass of ice, formed from many years of snow that has been compressed into hard ice. As well as ice, glaciers also contain rock and sediment which acts as like sandpaper on the land as the glacier flows across it.
Alpine glacier – A glacier that forms on a mountainside at high altitude and moves down valleys.
Ice sheet – A mass of glacial land ice extending more than 50,000 square kilometres. The two ice sheets on Earth today cover most of Greenland and Antarctica. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
Pupils will map the distribution of glaciers and identify that the following countries have glaciers:
Iceland, Antarctica (not a country but a continent), Afghanistan, Pakistan, China, India, Nepal, Bhutan, Myanmar, Chile, Peru, Ecuador, Iceland, Austria, Switzerland, Italy, France, Slovenia, Germany, Canada, the USA, Russia, New Zealand, Kenya, Tanzania, Uganda and the Democratic Republic of Congo
Pupils should be aware of the glacier as a system:
Pupils should be able to articulate the formation process:
· Snow falls on mountains
· It is so cold, it doesn’t melt over the summer months
· Each year another layer of snow falls, compressing the old layers. This is called ‘accumulation’.
· The air is forced out of the snow, turning it first to firn and then glacial ice
· The glacier moves downhill
· Ice is lost from the lower section of the glacier in the zone of ablation
· The very end of the glacier is called the snout
Pupils should understand the basics of how glaciers move:
Glaciers always flow downslope.
There are two processes:
· Internal Deformation – the intense pressure at the base of the glacier causes solid ice to move in a plastic-like manner.
· Basal Slip – liquid water at the base can act as a lubricant and allow the glacier to slide along. The water can either come from melt water entering through crevasses or ice melting under pressure at the base.
Climate governs the movement of glaciers:
· Ice sheets form in environments that are cold all year round, limiting the availability of water. They move slowly under internal deformation.
· Alpine glaciers are found at lower latitudes so have grater temperature variation throughout the year leading to greater availability of water. These glaciers move by basal sliding, tending to move more quickly and carry out more erosion.
Component Assessment – Short quiz at the proposed end of the unit
Component 2: Shaping the landscape – erosion, transport and deposition
There are three weathering process:
· Biological
· Chemical
· Freeze-thaw (mechanical/physical)
Freeze-thaw is the weathering process that takes places in glacial environments.
Glaciers carry out two forms of erosion:
1. Abrasion – pupils have already learnt about this is riparian and coastal context in the previous two units
· Abrasion is the sandpapering effect of the ice containing fragment of rock travelling over the Earth. Abrasion leaves behind smooth, polished rock surfaces that may have scratches called striations in them
2. Plucking – Meltwater beneath the glacier bonds the base to the rock underneath. As the glacier moves, chunks of rock loosened by freeze-thaw action are plucked away. These pieces of rock becomes embedded in the glacier and carry out the abrasion.
Sediment is carried on top of the glacier, inside it and dragged along the base. As the glacier moves forward, also pushes loose material in front of it, a process called ‘bulldozing’. The material is deposited when the ice melts. Most melting occurs as the snout so this is where most deposition takes place. The material the glacier dumps is called glacial till. It’s a jumble of rock, sand and clay.
Moraines are important features for understanding past environments. Terminal moraines, for example, mark the maximum extent of a glacier advance (see diagram below) and are used by glaciologists to reconstruct the former size of glaciers and ice sheets that have now shrunk or disappeared entirely
A terminal moraine is a moraine ridge that marks the maximum limit of a glacier advance. They form at the glacier terminus and mirror the shape of the ice margin at the time of deposition. The largest terminal moraines are formed by major continental ice sheets and can be over 100 m in height and 10s of kilometres long
Recessional moraines are found behind a terminal moraine limit and form during short-lived phases of glacier advance or standstill that interrupt a general pattern of glacier retreat
Lateral moraines form along the glacier side and consist of debris that falls or slumps from the valley wall or flows directly from the glacier surface. Where the rate of debris supply is high, lateral moraines can reach heights of more than 100 metres
Medial moraines form where lateral moraines meet at the confluence of two valley glaciers
Hummocky moraines form when a large chunk of a glacier breaks off and randomly dumps the sediment it was carrying. This leaves behind mounds of sediment – note not included on diagram.
Component Assessment – Short quiz at the proposed end of the unit
Component 3: Glacial landforms
Erosional Landforms:
Corries (also known as cirques or cwms) are large arm-chair shaped depressions in the side of a mountain created by the erosion power of a glacier.
Corrie formation:
· Snow collects in a sheltered hollow on the side of a mountain. This is usually on North-facing slopes in the northern hemisphere. The snow doesn't melt in the summer because it is high up, sheltered and cold.
· Every winter, more snow collects in the hollow. This becomes compacted and the air is squeezed out leaving ice.
· The back wall of the corrie gets steeper due to freeze-thaw weathering and plucking.
· The base of the corrie becomes deeper due to abrasion.
· As the glacier gets heavier it moves downhill. The glacier moves out of the hollow in a circular motion called rotational slip.
· Due to less erosion at the front of the glacier a corrie lip is formed.
· After the glacier has melted a lake forms in the hollow. This is called a corrie lake or tarn.
An arête is a sharp ridge that separates two corries. See diagram below
A pyramidal peak is formed where three or more corries and arêtes meet. The glaciers have carved away at the top of a mountain, creating a sharply pointed summit such as Mont Blanc, The Matterhorn and Mount Everest.
U-shaped valleys – pupils should be remind of the v-shaped valleys river carve in the upper course. Glaciers usually follow the path of river valleys, widening it to create a u-shape as they move along it.
After the ice has retreated, a river often flows in the valley again but it much smaller than the valley so is called a misfit river.
Pupils should be able to identify these landforms on an OS Map
A hanging valley is a tributary valley that meet the main valley high above it, often creating s waterfall.
Truncated spurs are also formed from interlocking spurs (see previous rivers unit). This happens when the glacier erodes the protruding hard rock of the interlocking spur, clearing and straightening the valley.
Fjords are flooded u-shaped valleys. They are found in places where current or past glaciation occurred below sea level. Fjords are formed when a glacier retreats, after creating a u-shaped valley and the sea fills in the resulting valley floor as sea level rises. ‘Fjord’ is a Norwegian word. Norway has one of the best examples of a fjord coastline.
Depositional Landforms:
Erratics are large boulders that have been carried and deposited by a glacier. They are different to the underlying rock type. When the ice retreats, these boulders are striking reminders that the landscape was once glaciated.
Drumlins are smooth egg-shaped hills that are 100-800m long and 25-100m high. The exact mechanism of drumlin formation is not clearly understood (excellent example of how glaciology is still developing). It is thought that the glacier moves over previously deposited till, smoothing and shaping it. Drumlins often appear in groups called drumlin fields.
Component Assessment – Short quiz at the proposed end of the unit
Component 4: People and glaciers
Pupils will explore the legacy of the UK’s glaciated environments. They will gain an overview of land use in these landscapes:
· Farming – as glaciers scour the landscape they remove soil, once melted they leave behind thin, acidic soil which is poor for arable farming so is used mainly for sheep. Sheep can tolerate the cold, wet, windy conditions and poor vegetation. Soils in valleys tend to be thicker and richer due to deposition. The flat-bottoms of the valleys make them suitable for machinery so farming can be more productive. Crops include cereals, potatoes and winter feed for livestock (hay and silage). Lowland glaciated areas are sometimes covered by a layer of till which is very fertile e.g. East Anglia resulting in productive farmland that is used for intensive arable farming.
· Forestry – many upland glaciated areas of the UK are suited to forestry. Large plantation of coniferous trees have been planted throughout Scotland and northern England. Conifer trees are well adapted to cope with the poor soil and steep slopes. The trees are grown for 20-30 years then cut down for the construction industry or making paper.
· Quarrying – Upland glaciated areas are made of hard, resistant rock. This is quarried for a range of purposes such as construction and road building.
· Tourism – People like to visit upland glaciated environments to see the spectacular scenery and enjoy outdoor activities such as mountain biking, skiing and climbing.
This opportunities all provide employment in areas with few other opportunities.
Pupils will look at tourism in the Lake District in more detail as an example of economic opportunities in glaciated environments.
Key facts about the Lake District:
· Made a national park in 1951
· Has physical attractions such as lakes, mountains and outdoor activities such as walking, mountain biking, abseiling and rock climbing
· Has cultural attractions such as the landscapes that inspired Wordsworth and the home of Beatrix Potter
There are social, economic and environmental impacts of tourism in the Lake District.
Social:
· 40 million day-tripper and 6.6 million overnight guests visited in 2018, the area only has 40,000 residents
· Over 89% of visitors travel by car causing congestion on the narrow, winding roads
· House prices are high – 20% of properties are second homes or holidays rentals
· Jobs is tourism as seasonal, poorly paid and unreliable
Economic:
· Tourists generated £3 billion for the Lake District in 2019
· Tourism creates jobs for local people
· Traffic congestion slows down businesses
Environmental:
· Main tourist sites are overcrowded, problems with litter, damage to grass verges by cars and footpath are eroded
· Pollution from cars and boats on the lakes can damage ecosystems
· Walkers can damage farmland by trampling farmland or leaving litter and dogs can disturb sheep.
Approaches to managing tourism in the Lake District:
· Integrated transport planning offering tourists alternatives such as travelling to the area by train and travelling around by bus
· Traffic calming measures (speed bumps) have been installed in villages
· The Fix the Fells project is a partnership of six organisations lead by the National Trust. It maintains and repairs the upland paths preventing further erosion. This is vital work without which access to the fells would be limited with severe impacts on the tourism industry
· The Lake District Foundation Low Carbon Cottages - This scheme aims to reduce carbon emissions and running costs of traditionally built holiday cottages without damaging any of their essential character. Working with holiday cottage owners and letting companies, they want to prove that cottages can meet the highest of environmental standards without it costing the earth, either to the owners or to the holidaymakers.
Some of the economic activities can come into direct conflict with each other. Pupils will look at two examples, the construction of wind turbines and plans for a zip wire in the Lake District.
The wind turbines were constructed in 2012 to generate electricity for the Kirkstone Pass Inn which had previously relied on diesel generators. Some people feel that the turbines detract for the natural landscape whilst others argue that they are good for the environment and have secured the future of the pub thereby maintaining local jobs.
In 2014 a proposal was put forward to build four parallel mile long zip wires above Glenridding in the Lake District. Plans were eventually dropped. Pupils should consider whether the zip wires should have been built considering the economic benefit of job creation versus maintaining the vista.
Component Assessment – Short quiz at the proposed end of the unit
Knowledge & vocabulary
Substantive Knowledge
Glacier – A large mass of ice, formed from many years of snow that has been compressed into hard ice. As well as ice, glaciers also contain rock and sediment which acts as like sandpaper on the land as the glacier flows across it.
Alpine glacier – A glacier that forms on a mountainside at high altitude and moves down valleys.
Ice sheet – A mass of glacial land ice extending more than 50,000 square kilometres. The two ice sheets on Earth today cover most of Greenland and Antarctica. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
The following countries have glaciers: Afghanistan, Pakistan, China, India, Nepal, Bhutan, Myanmar, Chile, Peru, Ecuador, Iceland, Austria, Switzerland, Italy, France, Slovenia, Germany, Canada, the USA, Russia, New Zealand, Kenya, Tanzania, Uganda and the Democratic Republic of Congo
Antarctica and Iceland have ice sheets.
Glacier formation process:
· Snow falls on mountains
· It is so cold, it doesn’t melt over the summer months
· Each year another layer of snow falls, compressing the old layers. This is called ‘accumulation’.
· The air is forced out of the snow, turning it first to firn and then glacial ice
· The glacier moves downhill
· Ice is lost from the lower section of the glacier in the zone of ablation
· The very end of the glacier is called the snout
Glaciers always flow downslope.
There are two processes:
· Internal Deformation – the intense pressure at the base of the glacier causes solid ice to move in a plastic-like manner.
· Basal Slip – liquid water at the base can act as a lubricant and allow the glacier to slide along. The water can either come from melt water entering through crevasses or ice melting under pressure at the base.
Climate governs the movement of glaciers:
· Ice sheets form in environments that are cold all year round, limiting the availability of water. They move slowly under internal deformation.
· Alpine glaciers are found at lower latitudes so have grater temperature variation throughout the year leading to greater availability of water. These glaciers move by basal sliding, tending to move more quickly and carry out more erosion.
There are three weathering process:
· Biological
· Chemical
· Freeze-thaw (mechanical/physical)
Freeze-thaw is the weathering process that takes places in glacial environments.
Glaciers carry out two forms of erosion:
1. Abrasion – pupils have already learnt about this is riparian and coastal context in the previous two units
· Abrasion is the sandpapering effect of the ice containing fragment of rock travelling over the Earth. Abrasion leaves behind smooth, polished rock surfaces that may have scratches called striations in them
2. Plucking – Meltwater beneath the glacier bonds the base to the rock underneath. As the glacier moves, chunks of rock loosened by freeze-thaw action are plucked away. These pieces of rock becomes embedded in the glacier and carry out the abrasion.
Sediment is carried on top of the glacier, inside it and dragged along the base. As the glacier moves forward, also pushes loose material in front of it, a process called ‘bulldozing’. The material is deposited when the ice melts. Most melting occurs as the snout so this is where most deposition takes place. The material the glacier dumps is called glacial till. It’s a jumble of rock, sand and clay.
Moraines are important features for understanding past environments. Terminal moraines, for example, mark the maximum extent of a glacier advance (see diagram below) and are used by glaciologists to reconstruct the former size of glaciers and ice sheets that have now shrunk or disappeared entirely
A terminal moraine is a moraine ridge that marks the maximum limit of a glacier advance. They form at the glacier terminus and mirror the shape of the ice margin at the time of deposition. The largest terminal moraines are formed by major continental ice sheets and can be over 100 m in height and 10s of kilometres long
Recessional moraines are found behind a terminal moraine limit and form during short-lived phases of glacier advance or standstill that interrupt a general pattern of glacier retreat
Lateral moraines form along the glacier side and consist of debris that falls or slumps from the valley wall or flows directly from the glacier surface. Where the rate of debris supply is high, lateral moraines can reach heights of more than 100 metres
Medial moraines form where lateral moraines meet at the confluence of two valley glaciers
Hummocky moraines form when a large chunk of a glacier breaks off and randomly dumps the sediment it was carrying. This leaves behind mounds of sediment
Erosional Landforms:
Corries (also known as cirques or cwms) are large arm-chair shaped depressions in the side of a mountain created by the erosion power of a glacier.
Corrie formation:
· Snow collects in a sheltered hollow on the side of a mountain. This is usually on North-facing slopes in the northern hemisphere. The snow doesn't melt in the summer because it is high up, sheltered and cold.
· Every winter, more snow collects in the hollow. This becomes compacted and the air is squeezed out leaving ice.
· The back wall of the corrie gets steeper due to freeze-thaw weathering and plucking.
· The base of the corrie becomes deeper due to abrasion.
· As the glacier gets heavier it moves downhill. The glacier moves out of the hollow in a circular motion called rotational slip.
· Due to less erosion at the front of the glacier a corrie lip is formed.
· After the glacier has melted a lake forms in the hollow. This is called a corrie lake or tarn.
An arête is a sharp ridge that separates two corries. See diagram below
A pyramidal peak is formed where three or more corries and arêtes meet. The glaciers have carved away at the top of a mountain, creating a sharply pointed summit such as Mont Blanc, The Matterhorn and Mount Everest.
U-shaped valleys – pupils should be remind of the v-shaped valleys river carve in the upper course. Glaciers usually follow the path of river valleys, widening it to create a u-shape as they move along it.
After the ice has retreated, a river often flows in the valley again but it much smaller than the valley so is called a misfit river.
A hanging valley is a tributary valley that meet the main valley high above it, often creating s waterfall.
Truncated spurs are also formed from interlocking spurs (see previous rivers unit). This happens when the glacier erodes the protruding hard rock of the interlocking spur, clearing and straightening the valley.
Fjords are flooded u-shaped valleys. They are found in places where current or past glaciation occurred below sea level. Fjords are formed when a glacier retreats, after creating a u-shaped valley and the sea fills in the resulting valley floor as sea level rises.
Depositional Landforms:
Erratics are large boulders that have been carried and deposited by a glacier. They are different to the underlying rock type. When the ice retreats, these boulders are striking reminders that the landscape was once glaciated.
Drumlins are smooth egg-shaped hills that are 100-800m long and 25-100m high. It is thought that the glacier moves over previously deposited till, smoothing and shaping it. Drumlins often appear in groups called drumlin fields.
Economic opportunities in glaciated landscapes:
· Farming – as glaciers scour the landscape they remove soil, once melted they leave behind thin, acidic soil which is poor for arable farming so is used mainly for sheep. Sheep can tolerate the cold, wet, windy conditions and poor vegetation. Soils in valleys tend to be thicker and richer due to deposition. The flat-bottoms of the valleys make them suitable for machinery so farming can be more productive. Crops include cereals, potatoes and winter feed for livestock (hay and silage). Lowland glaciated areas are sometimes covered by a layer of till which is very fertile e.g. East Anglia resulting in productive farmland that is used for intensive arable farming.
· Forestry – many upland glaciated areas of the UK are suited to forestry. Large plantation of coniferous trees have been planted throughout Scotland and northern England. Conifer trees are well adapted to cope with the poor soil and steep slopes. The trees are grown for 20-30 years then cut down for the construction industry or making paper.
· Quarrying – Upland glaciated areas are made of hard, resistant rock. This is quarried for a range of purposes such as construction and road building.
· Tourism – People like to visit upland glaciated environments to see the spectacular scenery and enjoy outdoor activities such as mountain biking, skiing and climbing.
Key facts about the Lake District:
· Made a national park in 1951
· Has physical attractions such as lakes, mountains and outdoor activities such as walking, mountain biking, abseiling and rock climbing
· Has cultural attractions such as the landscapes that inspired Wordsworth and the home of Beatrix Potter
There are social, economic and environmental impacts of tourism in the Lake District.
Social:
· 40 million day-tripper and 6.6 million overnight guests visited in 2018, the area only has 40,000 residents
· Over 89% of visitors travel by car causing congestion on the narrow, winding roads
· House prices are high – 20% of properties are second homes or holidays rentals
· Jobs is tourism as seasonal, poorly paid and unreliable
Economic:
· Tourists generated £3 billion for the Lake District in 2019
· Tourism creates jobs for local people
· Traffic congestion slows down businesses
Environmental:
· Main tourist sites are overcrowded, problems with litter, damage to grass verges by cars and footpath are eroded
· Pollution from cars and boats on the lakes can damage ecosystems
· Walkers can damage farmland by trampling farmland or leaving litter and dogs can disturb sheep.
Approaches to managing tourism in the Lake District:
· Integrated transport planning offering tourists alternatives such as travelling to the area by train and travelling around by bus
· Traffic calming measures (speed bumps) have been installed in villages
· The Fix the Fells project is a partnership of six organisations lead by the National Trust. It maintains and repairs the upland paths preventing further erosion. This is vital work without which access to the fells would be limited with severe impacts on the tourism industry
· The Lake District Foundation Low Carbon Cottages - This scheme aims to reduce carbon emissions and running costs of traditionally built holiday cottages without damaging any of their essential character. Working with holiday cottage owners and letting companies, they want to prove that cottages can meet the highest of environmental standards without it costing the earth, either to the owners or to the holidaymakers.
The wind turbines were constructed in 2012 to generate electricity for the Kirkstone Pass Inn which had previously relied on diesel generators. Some people feel that the turbines detract for the natural landscape whilst others argue that they are good for the environment and have secured the future of the pub thereby maintaining local jobs.
In 2014 a proposal was put forward to build four parallel mile long zip wires above Glenridding in the Lake District. Plans were eventually dropped. Pupils should consider whether the zip wires should have been built considering the economic benefit of job creation versus maintaining the vista.
Disciplinary Knowledge
Glaciologists study glaciers. They use repeat photograph to examine whether a glacier is in retreat or advance. Glaciologists use hot water to carve caves underneath glaciers to study the processes taking place.
Glaciers are considered as systems with inputs, outputs and processes.
‘Fjord’ is a Norwegian word. Norway has one of the best examples of a fjord coastline.
The exact mechanism of drumlin formation is not clearly understood (excellent example of how glaciology is still developing).
The impacts of change are considered from different perspectives in geography. At KS3 and 4 level these perspectives are social, economic and environmental.
Subject methods and resources
· PPT to display LO, key terms, cloze statements, data, video clips and images
Prior Knowledge
Rivers and Coasts units – erosion and weathering principles
Assessment of components and summative assessment of the unit (composite).
Component 1
Component Assessment – Short quiz at the proposed end of the unit
Component 2
Component Assessment – Short quiz at the proposed end of the unit
Component 3
Component Assessment – Short quiz at the proposed end of the unit
Component 4
Component Assessment – Short quiz at the proposed end of the unit
Composite:
Low Stakes:
Cold-Calling with robust creation of a collaborative, supportive learning atmosphere i.e. no silly answers or questions, just opportunities to learn. Pupils to be offered opportunity to select a peer if they are unsure of the answer themselves after thinking time.
Mini whiteboards for answers to Do Now starters, low stakes for pupils but also handy for teacher to gain snapshot of class when held up
Think, pair, share giving pupils chance to think through their answers to more challenging questions
Likely misconceptions and suggested strategies to tackling them
Component 1: What are glaciers?
The significance and important of ice and glaciers is not likely to have occurred to pupils before, perhaps unless they have been skiing.
Pupils will begin this unit by watching a documentary ‘The Power of Ice’. This will provide them with an overview of the role of ice on Earth and also a mental image of ice covered landscapes when they are referred to in subsequent lessons.
Pupils should have a securing understanding of the following key terms:
Glacier – A large mass of ice, formed from many years of snow that has been compressed into hard ice. As well as ice, glaciers also contain rock and sediment which acts as like sandpaper on the land as the glacier flows across it.
Alpine glacier – A glacier that forms on a mountainside at high altitude and moves down valleys.
Ice sheet – A mass of glacial land ice extending more than 50,000 square kilometres. The two ice sheets on Earth today cover most of Greenland and Antarctica. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
Pupils will map the distribution of glaciers and identify that the following countries have glaciers:
Iceland, Antarctica (not a country but a continent), Afghanistan, Pakistan, China, India, Nepal, Bhutan, Myanmar, Chile, Peru, Ecuador, Iceland, Austria, Switzerland, Italy, France, Slovenia, Germany, Canada, the USA, Russia, New Zealand, Kenya, Tanzania, Uganda and the Democratic Republic of Congo
Pupils should be aware of the glacier as a system:
Pupils should be able to articulate the formation process:
· Snow falls on mountains
· It is so cold, it doesn’t melt over the summer months
· Each year another layer of snow falls, compressing the old layers. This is called ‘accumulation’.
· The air is forced out of the snow, turning it first to firn and then glacial ice
· The glacier moves downhill
· Ice is lost from the lower section of the glacier in the zone of ablation
· The very end of the glacier is called the snout
Pupils should understand the basics of how glaciers move:
Glaciers always flow downslope.
There are two processes:
· Internal Deformation – the intense pressure at the base of the glacier causes solid ice to move in a plastic-like manner.
· Basal Slip – liquid water at the base can act as a lubricant and allow the glacier to slide along. The water can either come from melt water entering through crevasses or ice melting under pressure at the base.
Climate governs the movement of glaciers:
· Ice sheets form in environments that are cold all year round, limiting the availability of water. They move slowly under internal deformation.
· Alpine glaciers are found at lower latitudes so have grater temperature variation throughout the year leading to greater availability of water. These glaciers move by basal sliding, tending to move more quickly and carry out more erosion.
Component Assessment – Short quiz at the proposed end of the unit
Component 2: Shaping the landscape – erosion, transport and deposition
There are three weathering process:
· Biological
· Chemical
· Freeze-thaw (mechanical/physical)
Freeze-thaw is the weathering process that takes places in glacial environments.
Glaciers carry out two forms of erosion:
1. Abrasion – pupils have already learnt about this is riparian and coastal context in the previous two units
· Abrasion is the sandpapering effect of the ice containing fragment of rock travelling over the Earth. Abrasion leaves behind smooth, polished rock surfaces that may have scratches called striations in them
2. Plucking – Meltwater beneath the glacier bonds the base to the rock underneath. As the glacier moves, chunks of rock loosened by freeze-thaw action are plucked away. These pieces of rock becomes embedded in the glacier and carry out the abrasion.
Sediment is carried on top of the glacier, inside it and dragged along the base. As the glacier moves forward, also pushes loose material in front of it, a process called ‘bulldozing’. The material is deposited when the ice melts. Most melting occurs as the snout so this is where most deposition takes place. The material the glacier dumps is called glacial till. It’s a jumble of rock, sand and clay.
Moraines are important features for understanding past environments. Terminal moraines, for example, mark the maximum extent of a glacier advance (see diagram below) and are used by glaciologists to reconstruct the former size of glaciers and ice sheets that have now shrunk or disappeared entirely
A terminal moraine is a moraine ridge that marks the maximum limit of a glacier advance. They form at the glacier terminus and mirror the shape of the ice margin at the time of deposition. The largest terminal moraines are formed by major continental ice sheets and can be over 100 m in height and 10s of kilometres long
Recessional moraines are found behind a terminal moraine limit and form during short-lived phases of glacier advance or standstill that interrupt a general pattern of glacier retreat
Lateral moraines form along the glacier side and consist of debris that falls or slumps from the valley wall or flows directly from the glacier surface. Where the rate of debris supply is high, lateral moraines can reach heights of more than 100 metres
Medial moraines form where lateral moraines meet at the confluence of two valley glaciers
Hummocky moraines form when a large chunk of a glacier breaks off and randomly dumps the sediment it was carrying. This leaves behind mounds of sediment – note not included on diagram.
Component Assessment – Short quiz at the proposed end of the unit
Component 3: Glacial landforms
Erosional Landforms:
Corries (also known as cirques or cwms) are large arm-chair shaped depressions in the side of a mountain created by the erosion power of a glacier.
Corrie formation:
· Snow collects in a sheltered hollow on the side of a mountain. This is usually on North-facing slopes in the northern hemisphere. The snow doesn't melt in the summer because it is high up, sheltered and cold.
· Every winter, more snow collects in the hollow. This becomes compacted and the air is squeezed out leaving ice.
· The back wall of the corrie gets steeper due to freeze-thaw weathering and plucking.
· The base of the corrie becomes deeper due to abrasion.
· As the glacier gets heavier it moves downhill. The glacier moves out of the hollow in a circular motion called rotational slip.
· Due to less erosion at the front of the glacier a corrie lip is formed.
· After the glacier has melted a lake forms in the hollow. This is called a corrie lake or tarn.
An arête is a sharp ridge that separates two corries. See diagram below
A pyramidal peak is formed where three or more corries and arêtes meet. The glaciers have carved away at the top of a mountain, creating a sharply pointed summit such as Mont Blanc, The Matterhorn and Mount Everest.
U-shaped valleys – pupils should be remind of the v-shaped valleys river carve in the upper course. Glaciers usually follow the path of river valleys, widening it to create a u-shape as they move along it.
After the ice has retreated, a river often flows in the valley again but it much smaller than the valley so is called a misfit river.
Pupils should be able to identify these landforms on an OS Map
A hanging valley is a tributary valley that meet the main valley high above it, often creating s waterfall.
Truncated spurs are also formed from interlocking spurs (see previous rivers unit). This happens when the glacier erodes the protruding hard rock of the interlocking spur, clearing and straightening the valley.
Fjords are flooded u-shaped valleys. They are found in places where current or past glaciation occurred below sea level. Fjords are formed when a glacier retreats, after creating a u-shaped valley and the sea fills in the resulting valley floor as sea level rises. ‘Fjord’ is a Norwegian word. Norway has one of the best examples of a fjord coastline.
Depositional Landforms:
Erratics are large boulders that have been carried and deposited by a glacier. They are different to the underlying rock type. When the ice retreats, these boulders are striking reminders that the landscape was once glaciated.
Drumlins are smooth egg-shaped hills that are 100-800m long and 25-100m high. The exact mechanism of drumlin formation is not clearly understood (excellent example of how glaciology is still developing). It is thought that the glacier moves over previously deposited till, smoothing and shaping it. Drumlins often appear in groups called drumlin fields.
Component Assessment – Short quiz at the proposed end of the unit
Component 4: People and glaciers
Pupils will explore the legacy of the UK’s glaciated environments. They will gain an overview of land use in these landscapes:
· Farming – as glaciers scour the landscape they remove soil, once melted they leave behind thin, acidic soil which is poor for arable farming so is used mainly for sheep. Sheep can tolerate the cold, wet, windy conditions and poor vegetation. Soils in valleys tend to be thicker and richer due to deposition. The flat-bottoms of the valleys make them suitable for machinery so farming can be more productive. Crops include cereals, potatoes and winter feed for livestock (hay and silage). Lowland glaciated areas are sometimes covered by a layer of till which is very fertile e.g. East Anglia resulting in productive farmland that is used for intensive arable farming.
· Forestry – many upland glaciated areas of the UK are suited to forestry. Large plantation of coniferous trees have been planted throughout Scotland and northern England. Conifer trees are well adapted to cope with the poor soil and steep slopes. The trees are grown for 20-30 years then cut down for the construction industry or making paper.
· Quarrying – Upland glaciated areas are made of hard, resistant rock. This is quarried for a range of purposes such as construction and road building.
· Tourism – People like to visit upland glaciated environments to see the spectacular scenery and enjoy outdoor activities such as mountain biking, skiing and climbing.
This opportunities all provide employment in areas with few other opportunities.
Pupils will look at tourism in the Lake District in more detail as an example of economic opportunities in glaciated environments.
Key facts about the Lake District:
· Made a national park in 1951
· Has physical attractions such as lakes, mountains and outdoor activities such as walking, mountain biking, abseiling and rock climbing
· Has cultural attractions such as the landscapes that inspired Wordsworth and the home of Beatrix Potter
There are social, economic and environmental impacts of tourism in the Lake District.
Social:
· 40 million day-tripper and 6.6 million overnight guests visited in 2018, the area only has 40,000 residents
· Over 89% of visitors travel by car causing congestion on the narrow, winding roads
· House prices are high – 20% of properties are second homes or holidays rentals
· Jobs is tourism as seasonal, poorly paid and unreliable
Economic:
· Tourists generated £3 billion for the Lake District in 2019
· Tourism creates jobs for local people
· Traffic congestion slows down businesses
Environmental:
· Main tourist sites are overcrowded, problems with litter, damage to grass verges by cars and footpath are eroded
· Pollution from cars and boats on the lakes can damage ecosystems
· Walkers can damage farmland by trampling farmland or leaving litter and dogs can disturb sheep.
Approaches to managing tourism in the Lake District:
· Integrated transport planning offering tourists alternatives such as travelling to the area by train and travelling around by bus
· Traffic calming measures (speed bumps) have been installed in villages
· The Fix the Fells project is a partnership of six organisations lead by the National Trust. It maintains and repairs the upland paths preventing further erosion. This is vital work without which access to the fells would be limited with severe impacts on the tourism industry
· The Lake District Foundation Low Carbon Cottages - This scheme aims to reduce carbon emissions and running costs of traditionally built holiday cottages without damaging any of their essential character. Working with holiday cottage owners and letting companies, they want to prove that cottages can meet the highest of environmental standards without it costing the earth, either to the owners or to the holidaymakers.
Some of the economic activities can come into direct conflict with each other. Pupils will look at two examples, the construction of wind turbines and plans for a zip wire in the Lake District.
The wind turbines were constructed in 2012 to generate electricity for the Kirkstone Pass Inn which had previously relied on diesel generators. Some people feel that the turbines detract for the natural landscape whilst others argue that they are good for the environment and have secured the future of the pub thereby maintaining local jobs.
In 2014 a proposal was put forward to build four parallel mile long zip wires above Glenridding in the Lake District. Plans were eventually dropped. Pupils should consider whether the zip wires should have been built considering the economic benefit of job creation versus maintaining the vista.
Component Assessment – Short quiz at the proposed end of the unit
Knowledge & vocabulary
Substantive Knowledge
Glacier – A large mass of ice, formed from many years of snow that has been compressed into hard ice. As well as ice, glaciers also contain rock and sediment which acts as like sandpaper on the land as the glacier flows across it.
Alpine glacier – A glacier that forms on a mountainside at high altitude and moves down valleys.
Ice sheet – A mass of glacial land ice extending more than 50,000 square kilometres. The two ice sheets on Earth today cover most of Greenland and Antarctica. Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
The following countries have glaciers: Afghanistan, Pakistan, China, India, Nepal, Bhutan, Myanmar, Chile, Peru, Ecuador, Iceland, Austria, Switzerland, Italy, France, Slovenia, Germany, Canada, the USA, Russia, New Zealand, Kenya, Tanzania, Uganda and the Democratic Republic of Congo
Antarctica and Iceland have ice sheets.
Glacier formation process:
· Snow falls on mountains
· It is so cold, it doesn’t melt over the summer months
· Each year another layer of snow falls, compressing the old layers. This is called ‘accumulation’.
· The air is forced out of the snow, turning it first to firn and then glacial ice
· The glacier moves downhill
· Ice is lost from the lower section of the glacier in the zone of ablation
· The very end of the glacier is called the snout
Glaciers always flow downslope.
There are two processes:
· Internal Deformation – the intense pressure at the base of the glacier causes solid ice to move in a plastic-like manner.
· Basal Slip – liquid water at the base can act as a lubricant and allow the glacier to slide along. The water can either come from melt water entering through crevasses or ice melting under pressure at the base.
Climate governs the movement of glaciers:
· Ice sheets form in environments that are cold all year round, limiting the availability of water. They move slowly under internal deformation.
· Alpine glaciers are found at lower latitudes so have grater temperature variation throughout the year leading to greater availability of water. These glaciers move by basal sliding, tending to move more quickly and carry out more erosion.
There are three weathering process:
· Biological
· Chemical
· Freeze-thaw (mechanical/physical)
Freeze-thaw is the weathering process that takes places in glacial environments.
Glaciers carry out two forms of erosion:
1. Abrasion – pupils have already learnt about this is riparian and coastal context in the previous two units
· Abrasion is the sandpapering effect of the ice containing fragment of rock travelling over the Earth. Abrasion leaves behind smooth, polished rock surfaces that may have scratches called striations in them
2. Plucking – Meltwater beneath the glacier bonds the base to the rock underneath. As the glacier moves, chunks of rock loosened by freeze-thaw action are plucked away. These pieces of rock becomes embedded in the glacier and carry out the abrasion.
Sediment is carried on top of the glacier, inside it and dragged along the base. As the glacier moves forward, also pushes loose material in front of it, a process called ‘bulldozing’. The material is deposited when the ice melts. Most melting occurs as the snout so this is where most deposition takes place. The material the glacier dumps is called glacial till. It’s a jumble of rock, sand and clay.
Moraines are important features for understanding past environments. Terminal moraines, for example, mark the maximum extent of a glacier advance (see diagram below) and are used by glaciologists to reconstruct the former size of glaciers and ice sheets that have now shrunk or disappeared entirely
A terminal moraine is a moraine ridge that marks the maximum limit of a glacier advance. They form at the glacier terminus and mirror the shape of the ice margin at the time of deposition. The largest terminal moraines are formed by major continental ice sheets and can be over 100 m in height and 10s of kilometres long
Recessional moraines are found behind a terminal moraine limit and form during short-lived phases of glacier advance or standstill that interrupt a general pattern of glacier retreat
Lateral moraines form along the glacier side and consist of debris that falls or slumps from the valley wall or flows directly from the glacier surface. Where the rate of debris supply is high, lateral moraines can reach heights of more than 100 metres
Medial moraines form where lateral moraines meet at the confluence of two valley glaciers
Hummocky moraines form when a large chunk of a glacier breaks off and randomly dumps the sediment it was carrying. This leaves behind mounds of sediment
Erosional Landforms:
Corries (also known as cirques or cwms) are large arm-chair shaped depressions in the side of a mountain created by the erosion power of a glacier.
Corrie formation:
· Snow collects in a sheltered hollow on the side of a mountain. This is usually on North-facing slopes in the northern hemisphere. The snow doesn't melt in the summer because it is high up, sheltered and cold.
· Every winter, more snow collects in the hollow. This becomes compacted and the air is squeezed out leaving ice.
· The back wall of the corrie gets steeper due to freeze-thaw weathering and plucking.
· The base of the corrie becomes deeper due to abrasion.
· As the glacier gets heavier it moves downhill. The glacier moves out of the hollow in a circular motion called rotational slip.
· Due to less erosion at the front of the glacier a corrie lip is formed.
· After the glacier has melted a lake forms in the hollow. This is called a corrie lake or tarn.
An arête is a sharp ridge that separates two corries. See diagram below
A pyramidal peak is formed where three or more corries and arêtes meet. The glaciers have carved away at the top of a mountain, creating a sharply pointed summit such as Mont Blanc, The Matterhorn and Mount Everest.
U-shaped valleys – pupils should be remind of the v-shaped valleys river carve in the upper course. Glaciers usually follow the path of river valleys, widening it to create a u-shape as they move along it.
After the ice has retreated, a river often flows in the valley again but it much smaller than the valley so is called a misfit river.
A hanging valley is a tributary valley that meet the main valley high above it, often creating s waterfall.
Truncated spurs are also formed from interlocking spurs (see previous rivers unit). This happens when the glacier erodes the protruding hard rock of the interlocking spur, clearing and straightening the valley.
Fjords are flooded u-shaped valleys. They are found in places where current or past glaciation occurred below sea level. Fjords are formed when a glacier retreats, after creating a u-shaped valley and the sea fills in the resulting valley floor as sea level rises.
Depositional Landforms:
Erratics are large boulders that have been carried and deposited by a glacier. They are different to the underlying rock type. When the ice retreats, these boulders are striking reminders that the landscape was once glaciated.
Drumlins are smooth egg-shaped hills that are 100-800m long and 25-100m high. It is thought that the glacier moves over previously deposited till, smoothing and shaping it. Drumlins often appear in groups called drumlin fields.
Economic opportunities in glaciated landscapes:
· Farming – as glaciers scour the landscape they remove soil, once melted they leave behind thin, acidic soil which is poor for arable farming so is used mainly for sheep. Sheep can tolerate the cold, wet, windy conditions and poor vegetation. Soils in valleys tend to be thicker and richer due to deposition. The flat-bottoms of the valleys make them suitable for machinery so farming can be more productive. Crops include cereals, potatoes and winter feed for livestock (hay and silage). Lowland glaciated areas are sometimes covered by a layer of till which is very fertile e.g. East Anglia resulting in productive farmland that is used for intensive arable farming.
· Forestry – many upland glaciated areas of the UK are suited to forestry. Large plantation of coniferous trees have been planted throughout Scotland and northern England. Conifer trees are well adapted to cope with the poor soil and steep slopes. The trees are grown for 20-30 years then cut down for the construction industry or making paper.
· Quarrying – Upland glaciated areas are made of hard, resistant rock. This is quarried for a range of purposes such as construction and road building.
· Tourism – People like to visit upland glaciated environments to see the spectacular scenery and enjoy outdoor activities such as mountain biking, skiing and climbing.
Key facts about the Lake District:
· Made a national park in 1951
· Has physical attractions such as lakes, mountains and outdoor activities such as walking, mountain biking, abseiling and rock climbing
· Has cultural attractions such as the landscapes that inspired Wordsworth and the home of Beatrix Potter
There are social, economic and environmental impacts of tourism in the Lake District.
Social:
· 40 million day-tripper and 6.6 million overnight guests visited in 2018, the area only has 40,000 residents
· Over 89% of visitors travel by car causing congestion on the narrow, winding roads
· House prices are high – 20% of properties are second homes or holidays rentals
· Jobs is tourism as seasonal, poorly paid and unreliable
Economic:
· Tourists generated £3 billion for the Lake District in 2019
· Tourism creates jobs for local people
· Traffic congestion slows down businesses
Environmental:
· Main tourist sites are overcrowded, problems with litter, damage to grass verges by cars and footpath are eroded
· Pollution from cars and boats on the lakes can damage ecosystems
· Walkers can damage farmland by trampling farmland or leaving litter and dogs can disturb sheep.
Approaches to managing tourism in the Lake District:
· Integrated transport planning offering tourists alternatives such as travelling to the area by train and travelling around by bus
· Traffic calming measures (speed bumps) have been installed in villages
· The Fix the Fells project is a partnership of six organisations lead by the National Trust. It maintains and repairs the upland paths preventing further erosion. This is vital work without which access to the fells would be limited with severe impacts on the tourism industry
· The Lake District Foundation Low Carbon Cottages - This scheme aims to reduce carbon emissions and running costs of traditionally built holiday cottages without damaging any of their essential character. Working with holiday cottage owners and letting companies, they want to prove that cottages can meet the highest of environmental standards without it costing the earth, either to the owners or to the holidaymakers.
The wind turbines were constructed in 2012 to generate electricity for the Kirkstone Pass Inn which had previously relied on diesel generators. Some people feel that the turbines detract for the natural landscape whilst others argue that they are good for the environment and have secured the future of the pub thereby maintaining local jobs.
In 2014 a proposal was put forward to build four parallel mile long zip wires above Glenridding in the Lake District. Plans were eventually dropped. Pupils should consider whether the zip wires should have been built considering the economic benefit of job creation versus maintaining the vista.
Disciplinary Knowledge
Glaciologists study glaciers. They use repeat photograph to examine whether a glacier is in retreat or advance. Glaciologists use hot water to carve caves underneath glaciers to study the processes taking place.
Glaciers are considered as systems with inputs, outputs and processes.
‘Fjord’ is a Norwegian word. Norway has one of the best examples of a fjord coastline.
The exact mechanism of drumlin formation is not clearly understood (excellent example of how glaciology is still developing).
The impacts of change are considered from different perspectives in geography. At KS3 and 4 level these perspectives are social, economic and environmental.
Subject methods and resources
· PPT to display LO, key terms, cloze statements, data, video clips and images
Prior Knowledge
Rivers and Coasts units – erosion and weathering principles
Assessment of components and summative assessment of the unit (composite).
Component 1
Component Assessment – Short quiz at the proposed end of the unit
Component 2
Component Assessment – Short quiz at the proposed end of the unit
Component 3
Component Assessment – Short quiz at the proposed end of the unit
Component 4
Component Assessment – Short quiz at the proposed end of the unit
Composite:
Low Stakes:
Cold-Calling with robust creation of a collaborative, supportive learning atmosphere i.e. no silly answers or questions, just opportunities to learn. Pupils to be offered opportunity to select a peer if they are unsure of the answer themselves after thinking time.
Mini whiteboards for answers to Do Now starters, low stakes for pupils but also handy for teacher to gain snapshot of class when held up
Think, pair, share giving pupils chance to think through their answers to more challenging questions
Likely misconceptions and suggested strategies to tackling them