Glaciated Landscapes and Change Flashcards

Question

What is an Ice Sheet?

Answer 1

Complete submergence of regional topography; forms a gently sloping dome of ice several kilometres thick in the centre. Average size - 10-100,000 km². Example - Greenland and Antarctica.

Answer 2

Smaller version of ice sheet occuplying upland areas; outlet glacier and ice sheet drain both ice sheets and ice caps. Average size - 3-10,000 km². Example - Vatnajökull, Iceland.

Answer 3

Ice covering an upland area, but not thick enough to bury topography; many do not extend beyond highland source. Average size - 10-10,000 km² Example - Patagonia, Chile and Columbia Canada.

Answer 4

Glacier confined between valley walls and terminating in a narrow tongue; forms from ice caps/sheets or cirques; may terminate in sea as tidewater glacier. Average size - 3-1,500 km². Example - Aletsch Glacier, Switzerland and Athabasca, Canada.

Answer 5

Valley glacier which extends beyond the end of a mountain valley into a flatter area and spreads out like a fan. Average size - 3-1,000 km². Example - Malaspina, Alaska.

Answer 6

Smaller glacier occupying a hollow on the mountain side - carves out a corrie or cirque; smaller version is known as a niche glacier. Average size - 0.5-8 km². Example - Hodges Glacier, Grytviken, Sotuh Gerogia.

Answer 7

Large are of floating glacier ice extending from the coast where several glaciers have reached the sea and merge. Average size - 10-100,000 km². Example - Ronne and Ross Ice Shelf, Antarctica.

Answer 8

The addition of mass to the glacier (inputs) e.g. avalanches from slopes above, rock debris, wind deposition, meltwater, precipitation (mainly snow).

Answer 9

The loss of mass from the glacier (outputs) e.g. evaporation (sublimation), rock debris, breaking away of ice blocks and ice bergs (calving), melting (water).

Answer 10

Using the total accumulation and ablation within a year.

Answer 11

-Glacials gain mass through the transformation of snow into ice and then flow downhill (in response to gravity) and eventually lose mass due to melting. -Glaciers accumulate mass from snow falling onto its surface, snow avalanching from the valley sides and by accretion of rime ice by direct freezing of atmospheric moisture onto the glacier. -Glaciers lose or ablate mass by melting as a result of warm air temperature or applied pressure, evaporation, wind erosion or by calving into icebergs along a floating ice front. -In extremely cold and arid areas, such as the interior of Antarctica ice, mass can also be lost by sublimation (ice changing directly into water vapour).

Answer 12

It involves viewing any part of the physical or human as a entity that consists of stores and transfers of energy and matter, and operates because it receives a constant supply of energy and matter, which in turn are lost from the system as outputs. Changes in the level of inputs may cause instability within the system, and in response to the new amounts of energy, the system initiates feeback processes. The snowballing effect may ultimately cause a shift in the system to a new state of equilibirum.

Answer 13

Glaciers gain mass in the accumulation zone, i.e. the upper part of the glacier where input (winter snowfall etc) exceeds output (summer melting etc). Mass is lost in the lower ablation zone where outputs exceed inputs. At the transition between the two zones accumulation equals ablation. This boundary is called the equilibrium line, which in turn approximately coincides with the position of the snowline. The gains and the loses of ice experienced by a glacier constitute its mass balance or glacial budget.

Answer 14

-In the South Pole there is more present day ice coverage and less late pleistocene ice sheets -> hasn't reduced as much. -In the Northern hemisphere there is a lot more of the lat pleistocene ice sheet have melted -> around northern Europe (Russia, the UK and Skandinavida). -The late Pleistocene ice sheet in South America have all melted. -The Laurentide and Cordilleran ice sheets covered east and west of North America stertching around 3000 km in width. -Major ice extentsions were over North America and Europe (this grew to a thickness of around 3000-4000 m). -At present, ice covers over 10% of the Earth's land area which accounts for 75% of the world's freshwater (about 1.8% of all water on Earths). -Ice covers at the Pleistocene maximum was more than 3x greater than the present day. -About 85% of all current glacier ice is contained in Antarctica.

Answer 15

-Latitude -Altitude -Aspect

Answer 16

Particulary important fro polar ice masses. In high latitude the sun's rays hits the ground at a lower angle, so the solar energy received must heat a larger area.

Answer 17

Particulary important for alpine glaciers. High altitudes are impacted by the environmental lapse rate (ELR) whereby tempertaure decline by 1°c for every 100m above sea level.

Answer 18

This can determine the amount of snow falling and where it settles. In the northern hemisphere, north and east facing slopes are both more sheltered and shadier.

Answer 19

-Permafrost is permanently frozen ground where subsoil temperatures remain below 0°c fro at least two consecutive years. -Around 20% of the Earth experiences periglacial conditions - mainly in the northern hemisphere. During the Pleistocene glaical periods, this was higher at 33% and at much lower latitudes than today.

Answer 20

Forms in the coldest areas of the world where mean annual temperatures are below -6°c. It is found at the highest latitudes. It can extend downwards for hundreds of metres.

Answer 21

It is shallower and permanently frozen ground is fragmented by patches of unfrozen ground (talik). The surface layer of the ground melts during the summer months.

Answer 22

It occurs where the mean annual temperature is only just below freezing and permafrost covers amounts of less than 50% of the slandscape.

Answer 23

It occurs when less than 10% of an area is affected.

Answer 24

-Snow falls on the 1st layer and collects on the glacier. Fresh layers of snow fall each day and build up. -As snow becomes compacted it starts freezing together on the 2nd layer, becoming quite granular -> this is called granular snow. -As the granular snow becomes increasingly compressed it forms névé or firm on the 3rd layer. -As the snow layers increase and the process continues and the layers become deeper. The névé (or firm) transforms into glacier ice on the 4th layer.

Answer 25

-Amount of precipitation -Average temperatures -Levels of solar insolation -Levels of wind speed -Latitude -Continentality (distance from the sea as seas/waters are warmer influencing temperature around glaciers/permafrost).

Answer 26

Positive and negative regimes -A positive regime is when the glacier is increasing in mass i.e. accumulation exceeding ablation during the winter period. -A negative regime is when the glacier is decreasing in mass i.e. when ablation exceeds accumulation during the summer.

Answer 27

Trends and Glacier Health -Trends van be summarised over a decade from annual net balance. -These long term trends determine the 'health' of a glacier and whether it will significantly advance or retreat and if thinning/retreating contributes to increased concerns over global sea level rises. -Currently it's estimated that nearly 75% of the world's ice masses are experiencing 'rising trends' in their net negative balances.

Answer 28

The difference between the accumulation and ablation. Cumulative is the difference added overtime.

Answer 29

-A negative feedback cycle acts to minimise the effect of new inputs in order to regain stability and equilibrium. -E.g. if there is more snowfall, the glacier would advance (grow) meaning more ice would enter the ablation zone so more snowmelt would occur. -This would mean that a balance would be gained whereby the input of snowfall would equal the output of snowmelt. -The system remains balanced.

Answer 30

-A positive feedback cycle amplifies the effects of an input which would cause a shift in the system. -E.g. if a glacier has a positive mass balance and the glacier surface area is increasing, there will be an increase in ice albedo. This will cause a further reduction in air temperature, thus increasing accumulation and initiating a positive feedback cycle in which the glacier will continue to advance (this works the other way round too). -The system will not be balanced.

Answer 31

-One of the world's two remaining ice sheets. -Covers an area of 1.7 million km². -It conatins more than 2.5 million km³ of stored ice. -In the centre, ice is 3 km thick which depresses the earth's crust by 1km in depth. -A number of changes have occured to the mass balance of the ice sheet recently. -Accumulation of snowfall in the central area is +520 km -Ablation of melting and edges is -290 -Ablation by calving icebergs is -200 -Ablation of sublimation is -60 -Total ablation is -550 -Mass balance is -30

Answer 32

-Snow/ice melt due to the greenhouse effect -> melting reveals bare ground -> albedo effect os reduced, accelerating warmong of land -> less reflection of solar radiation -> increase in global warming (and the cycle repeats). -Snow/ice melt due to the greenhouse effect -> melting reveals bare ground -> methane released in to the atmopshere -> increase in global warming (and the cycle repeats).

Answer 33

-This is the temperature at which the ice is on the verge of melting. -On the surface of the glacier the PMP is usually 0°c. -However, this can be lower with a glacier due to the pressure (weight of the glacier). -This means that at the base of the glacier, ice can melt at below 0°c, allowing the ice to move with the help of melt water even if the air temperature is below freezing point.

Answer 34

-Inter-granular movement: individual ice crystals slip and slide over eachother. -Intra-granular movement: ice crystals deform due to stress within the ice and eventually moves downhill under the influence of gravity.

Answer 35

-Basal slip which is further subdivided into creep and regelation, extending and compressing flow, surges. -Internal deformation.

Answer 36

This occurs when the base of the glacier is at the pressure melting point, which means that meltwater is present and acts as a lubricant, enabling the glacier to slide more rapidly over the bedrock. Basal slip can be further subdivided into several processes.

Answer 37

Basal slip is enhanced by obstacles on the valley floor. A large bedrock obstacle (>1m wide) causes an increase in pressure, which makes the ice plastically deform around the feature (creep). Smaller obstacles (<1m wide) will cause pressure-melting, increasing ice movement by basal slip. The ice refreezes on the downglacier (lee) side of the obstacle. The process of melting under pressure and refreezing is known as regelation.

Answer 38

Over steep slopes, the rate of basal slip will increase and the ice will accelerate and thin. This is known as extending flow. Over shallower slopes, basal slip slows and the ice decelerates and thickens. This is known as compressing flow.

Answer 39

In these short-lived events a glacier can advance substantially, moving up to 100 times faster than normal. Thry has various causes (e.g. earthquakes) but the most common is enhanced basal sliding triggered by the builf-up of meltwater at the ice-rock interface.

Answer 40

This occurs when the weight of glacier ice and gravity causes the ice crystals to deform, so that the glacier moves downslope very slowly.

Answer 41

Internal deformation.

Answer 42

-Altitude -Gravity and gradient slope -Ice mass/thickness -Rock type -Ice movement -Meltwater

Answer 43

It affects precipitation and temperature. Greater precipitation and lower temperatues increase the supply of snow and ice, and so its mass balance.

Answer 44

Gravity causes ice to move; the steeper the gradient, the faster it flows.

Answer 45

The heavier/greater the mass, the greater the pressure in the ice which causes faster movement.

Answer 46

If rock is permeable then meltwater may percolate through, slwoing the movement of the glacier. If rocks are impermeable there will be more meltwater, causing the glacier to move quicker.

Answer 47

Colder ice moves slowly as it does not deform as easily and it stays stuck to the bedrock.

Answer 48

The more melwater there is the faster the movement as basal slippage increases.

Answer 49

The process by which surface sediment is incorporated into a fluid flow (e.g. air, ice or water) as part of erosion.

Answer 50

Mainly weathered material carried on top of the ice. This includes material falling from hillsides being washed or blown down, plus atmospheric fallout such as volcanic ash (a common feature in Icelandic glaciers).

Answer 51

Formally supraglacial material, but now buried by fresh snow and carried within the ice.

Answer 52

Material carried below the ice. This includes material eroded from the glacier bed and valley walls, material frozen to the base from subglacial streams, as well as englacial material that has worked its way down through the glacier or ice sheet.

Answer 53

This occurs when material is released from the ice at the margins or base of the glacier. Deposition may occur directly on the ground (ice contact) or sediments may be released into meltwater, sometimes over distances of many kilometres. Deposition mechanisms include: release of debris by melting or sublimation of the surrounding ice, lodgement o debris by friction against the bed, deposition of material from meltwater, and disturbance and remodelling of previously deposited sediments.

Answer 54

A crack in a rock can fill with water which then freezes as the temperature drops. As the ice expands, it pushes the crack apart, making it larger, weakening the rocks.

Answer 55

Meltwater at the base of the glacier freezes into the rock. As the ice moves downhill, it plucks and removes rock from the bedrock.

Answer 56

Plucked rock fragments scratch and scrape the bedrock.

Answer 57

Where ice thickens and erosion is reduced.

Answer 58

-Since satellite measurements started in 1979, about 1/2 of the summer sea ice volume in the Arctic has been lost. -This has effects on marine ecosystems, ocean circulation and potential weather events further south of the Arctic. - The quality of the ice is also changing as the old ice is being replaced by new ice which contains more salty water, so it’s more subject to melting whereas the old snow is mostly from snow precipitations and is a source of freshwater.

Answer 59

-Climate change is more evident in the Arctic with warming at twice the global rate. -The sea ice edge supports a large and distinct biological community of specified plants and animals that have evolved to adopt to the place. Species that depend on sea ice face extinction if most of the sea ice is lost. -The main driver for removing ice through melting is the direct- melting from contact with warm ocean currents. A second driver is wind pushing the ice out of the Arctic. Sea ice is also crucial for the energy balance on Earth. Areas that have lost the sea ice cover absorb almost all incoming solar radiation. -In summer, the sea ice cover helps cooling our planet as it effectively reflects solar radiation. When the ice disappears, more heat is being absorbed by the ocean, amplifying the warming effects in the Arctic. This is called the Albedo effect.

Answer 60

-During the MOSAIC expedition in 2019 -2020 a team of researchers drifted with the sea ice for a full year. The amount of data collected is unique in the history of polar exploration and will be analysed by the scientific community in the future. -The Nansen Legacy is a Norwegian governmental research project set up to monitor and understand these widespread changes to the Barents Sea environment. -The Synoptic Arctic Survey aims to understand ongoing transformations by launching an international research program crossing the entire Arctic and observe the state of the Arctic climate system. -The UN Decade of Ocean Science for Sustainable Development (2021-2030) hosts several ocean science programmes and activities to address knowledge gaps in the Arctic Ocean.

Answer 61

-Sea ice retreating means that the Arctic region is becoming easier accessible for commercial activity such as fisheries, shipping, tourism and exploration of new resources and rare minerals on the ocean floor. This new accessibility gives new dilemmas for policies and attracts new geopolitical attention. -The Arctic represents one of the world’s last wilderness and fragile ecosystems. In 2015 most of the world nations signed the Paris Agreement. This is a framework to avoid dangerous climate change by limiting global warming to below 2°C and make effort to limit warming to 1.5°C. While implementation of renewable energy is underway, we are currently nowhere near fulfilling the 2°C target, and on a path to losing the Arctic Sea Ice entirely within the next 50 years.

Answer 62

-Cirques (corrie or cwm) (e.g. Cwm Idwal, Snowdonia) -Arête (e.g. Striding Edge, Lake District) -Pyramidal peak (e.g. The Matterhorn, Alps) -Glacial trough (e.g. Nant Ffrancon Valley, Snowdonia) -Truncated spur (e.g. Lake District) -Hanging valley (e.g. Pistyll Rhaeadr, Berwyn Mountains, Wales) -Ribbon lake (e.g. Llyn Ogwen) -Roche mountonnée (e.g. Lembert Dome, Yosemite National Park, California) -Knock and lochan (e.g. Shetland Islands, Scotland) -Crag and tail (e.g. Castle Rock, Edinburgh)

Answer 63

-An amphitheatre-shaped depsression in the mountainside with a steep back wall and a rock lip. The name given to this landfrom depends on its location, e.g. a cwm is found in Wales. -A large rounded hollow high on a mountainside is eroded and deepend by plucking and abrasion due to the rotational ice movement of a cirque glacier.

Answer 64

-A narrow, knife-edged ridge between two cirques. -Plucking and abrasion on the back wall of two cirques on a mountainside mean they erode backwards towards one another, creating a narrow ridge. Freeze-thaw action is also important.

Answer 65

-A pointed mountain peak with three or more cirques. -The erosional processes within nearby cirques mean they erode backwards towards eachother, creating a sharp, pointed mountain summit. Plucking is important.

Answer 66

-A U-shaped valley with steep sides and a wide, flat floor. -A V-shaped river valley is widened and deepened as a result of powerful plucking and abrasion by a valley glacier, which goes through the landscape rather than around it.

Answer 67

-A steep rocky valley side where spurs of a river valley used to interlock before glaciation. -Valley glaciers are less flexible than rivers and remove the ends of interlocking spurs by plucking and abrasion as they move down the river valley.

Answer 68

-A small trubutary V-shaped or small U-shaped valley high above the main glacial trough floor, often with a waterfal as the river flows over the edge. -Powerful thicker glacial ice in the main glacial trough eroded vertically downwards more rapidly than thinner ice or rivers in tributary valleys. The floor of the tributary valleys are left high above the main valley floor.

Answer 69

-A long, narrow lake along the flood of a glacial trough. -Areas of increased plucking and abrasion by the valley glacier deepn part of the valley floor, as a result of either the confluence of glaciers or weaker rocks. Sometimes the lake forms behind a terminal moraine after glaciation

Answer 70

-A mass of bare rock on the valley floor with a smouth stoss (up-valley side) and a steep jagged lee (down-valley side). -A more resistant rock outcrop causes ice movement by creep and regelation around it. As the ice slides over the rock, it scours and smoothes the stoss, while refreezing on the lee causes plucking.

Answer 71

-A lowland area with laternating small rock hills (knock) and hollows, often containing small lakes (lochan). -Scouring at the base of a glacier excavates areas of weaker rock, forming hollows that fit meltwater and precipitaion following ice retreat.

Answer 72

-A very large mass of hard rock forms a steep stoss with a gently sloping tail of deposited material. -A large mass of hard rock is resistant to ice scouring and created a steep stoss. Reduced glacier velocity on the lee protects softer rock and allows deposition, but the sheltering effect diminishes with distance, creating a sloping tail.

Answer 73

Large scale landforms, around 1km or greater in size and form the major elements in a glaciated highland landscape. (cirque, arête , pyramidal peak, glacial trough, truncated spur).

Answer 74

Medium-scale landforms largely found within macro features e.g. found on a valley floor. (roches mountonnée, hanging valley)

Answer 75

Small-scale landforms less than 1m long. (striations, chattermarks)

Answer 76

Those at higher altitude in hills and mountains.

Answer 77

Those at lower altitudes on valley floors and coastal plains.

Answer 78

Landscapes which are currently experiencing glaciation, active glacial processes and landform development e.g. Iceland.

Answer 79

Landscapes which are not currently characterised by glaciers but feature fossilised glacial landforms due to past glaciation e.g. the UK.

Answer 80

This occurs beneath the ice when subglacial debris becomes stuck on the glacier bed. It occurs when the friction between the subglacial debris and the bed becomes greater than the drag of ice over it.

Answer 81

This is a less common process associated with weak underlying bedrock, whereby the sediments are defined by the movement of the glaciers.

Answer 82

It occurs if high meltwater content causes the glacial debris to creep/slide or flow during deposition.

Answer 83

Refers to accumulation of glacial debris, whether it is dumped by an active glacier or left behind as a deposit after glacial retreat.

Answer 84

-Subglacial moraines, which are formed beneath the glacier. -Ice-marginal moraines, which are formed along the margins of a glacier.

Answer 85

Unsorted sediment.

Answer 86

Exposed rock on the valley side is weathered and fragments fall below onto the edge of the glacier, creating a ridge. This is then carried along the valley and deposited when the ice melts. Parallel to ice flow.

Answer 87

When two valley glaciers converge, two lateral moraines combine to form a medial moraine. Material is transported and deposited when the ice melts. Parallel to ice flow.

Answer 88

These represnt a stand-still during ice retrea. They appear like a series of ridges running across the valley behind the terminal moraine. A good indication of ice advance and retreat.

Answer 89

A ridge of moraine extends across the valley at the point of maximum advance before the glacier retreats.

Answer 90

-A typical drumlin is an oval or 'egg-shaped' hill made up of glacial till and aligned in the direction og ice flow. -They can vary in size but are commonly between 30-50 metres high and 500-1000 metres long. -They usually occur in clusters or 'swarms' on flat valley floors or lowland plains and forming 'basket of eggs' topography. -There is controversy over their formation. Although some have a rocky core (with sediment moulded around it), most do not. Some partly consist of fluvial sediments as well as glacial till, suggesting that meltwater played a part in their formation. -The plan is the gentle sloping, tapered end which occurs down-glacier and steep blunt end (stoss) is the up the glacier.

Answer 91

A measure of the proportion of the incoming solar radiation that is reflected by the surface back into the atmosphere and space.

Answer 92

The freezing and expansion of soil water causes the upwards dislocation of soil and rocks. As the ground freezez, large stones become chilled more rapidly than the soil. Water below such stones freezes and expands, pushing the stones upwards and forming small domes on the ground surface.

Answer 93

A combination of processes weakens and erodes the ground beneat a snow patch. These processes include freeze-thaw weathering, solifluction and meltwater erosion.

Answer 94

This is the downslope movement of the saturated active layer under the influence of gravity (known as gelifluction when it occurs over impermeable permafrost).

Answer 95

This is a mixture of water, mud and rock fragments flowing down the slopes of a volcano.

Answer 96

It is a powerful flood caused by the sudden discharge of a subglacial or ice moraine dammed lake. There is potential for these outburst floods whenever meltwater collects behind an ice or moraine obstruction. These large floods are a huge threat to people and property in inhabited mountain valleys around the world.

Answer 97

Flat plains consisting of glacial till that has been deposited.

Answer 98

Often more angular clasts as they are not ground down, and also the matrix of clay or silt-size particles (rock flour) e.g. till found in moraines.

Answer 99

Relatively rounded clasts because of the grinding taht occurs at the ice bed interface, sets within the matrix of clay or silt-size particles (rock flour) e.g.subglacial debris. -> In some areas, lodgement till can be remoulded into streamlined flutes. These flutes are elongated, low-relief ridges formed subglacially and oriented in the direction of glaicer flow. Groups of streamlined ridges are known as swarms.

Answer 100

They are a different rock type to the bedrock they sit on. Huge erracti boulders weighing up to 16,000 tonnes were carried 300km from the Canadian Rockies to the plains of Alberta by the Cordilleran Ice Sheet.

Answer 101

-Meltwater from glaciers pay a vital role in processes of erosion, entrainment, transport as well as deposition. -It is indirectly involved in the process of abrasion and plucking, but above all it plays a vital role in glacier movement by basal sliding and subglacial bed formation. -Meltwater beneath the glacier is also responsible for erosion; because of its fast speed and power it can scour and groove the underlying rock. -There are two main sources of meltwater from glacier: surface melting and basal melting.

Answer 102

Immediately in front of the glacier, close to the snout. Meltwater has the greatest power here so particle size may be large.

Answer 103

Further from the ice margin - meltwater streams tend to anastomose (link together), and form braided channels because of high daily and seasonal variation. Particle size is more rounded due to attrition.

Answer 104

Further from ice margin - broad flood plain - well sorted sediment and even smaller and rounded than medial zone.

Answer 105

-Generally smaller due to the lesser energy of the meltwater streams in comparison to valley glaciers. -Generally smoother and rounded through water contact and attrition, as well as being sorted and graded. -Are sorted horizontally, with the largest material found up-valley (nearest snout) and progressively finer material down0valley. -Stratified vertically with distinctive layers which reflect either seasonal or annual sediment accumulation. During summer months when discharge is high, heavier materials is found further down and deposited, during the winter only lighter material reaches this far so is deposited on top. Layers form of different sized sediment.

Answer 106

-The study of the flow of water through glaciers. -Water running off the surface of the glacier disappears through cracks and holes in the glaciers and powerful rivers emergy from the glacier snout. These subglacial drainage channels are connected to numerous subglacial lakes.-Saturated subglacial sediments have low shear strengths and deform easily -Glacier ice if permeable -The rate that water seeps through ice is so low that ice can generally be considered impermeable.

Answer 107

-Kame (e.g. The Fronthill ame in Pelham Ontario, Canada). -Kame terrace (e.g. The Lock Etive Kame Terrace, Scotland). -Esker (e.g. Maine, USA and Canada). -Sandur/outwash plain (e.g. Svalbard, Norway). -Kettle hole (e.g. Puslinch lake, Ontario, Canada). -Proglacial lake (e.g. Drkhat Lakes, Mongolia). -Meltwater channel (e.g. Newtondale, Yorkshire).

Answer 108

-An undulating mound of fluvio0glacial sand and gravel deposited on the valley floor near the glacier snout. -As meltwater streams emerge onto the outwash plain or proglacial lake at the glacier snouth, their velocity suddenly falls and sediments is deposited.

Answer 109

-A flat linear deposit of fluvio-glacial sand and gravel deposition-glacial sand and gravel. -During the summer the valley sides radiate heat, melting the edge of the glacier and forming meltwater streams, which deposit sediment. When the glacier retreats, the sediment will fall to the valley floor, forming a kame terrace.

Answer 110

-A long, narrow, sinuous (winf or meandering) ridge of fluvio-glaciated sand and gravel. -Subglacial streams can carry large amounts of rock debris due to their high hydrostatic pressure inside tunnels, the debris loads is deposited at a consistent rate and forms a ridge.

Answer 111

-A flat expanse of fluvio-glacial debris in fron of the glacier snout. -As meltwater streams energy from the glacier and enter lowland areas, they gradually lose their energy and deposit their debris load. The coarse gravels are deposited first, nearest the glacier, then the sand and finally clay (farthest from the glacier).

Answer 112

A circular depression, often forming a lake in an outwash plain. -As the glacier retreats, detached blcosk of ice rmain on the outwash plain. Meltwtaer streams flow over the ice, covering them in deposits of fluvio-glacial debris. Eventually the ice melts and debris subsides to form a depression whoch often fills iwth meltwater to forn a kettle-hole lake

Answer 113

-A lake formed in front of the glacier snout. -A proglaical lake is often formed by the damming action of a terminal or recessional moraine during the retreat of a melting glacier, or because hills block the escape of meltwater. It can slo be formed by meltwater trapped against an ice sheet as a result of isostatic depression of the crust around the ice.

Answer 114

-A narrow channel cut into bedrock or deposits, either underneath or along the front of an ice margin. -Meltwater can erode deep channels, even gorges, as a result of the high hydrostatic pressure within the glacier and their high sediemnt load. They have some unique characterics: under hydrostatic pressure beneath the glacier, they are able to flow uphill and they are often larger than post glacial streams; and braiding of proglacial meltwater channels is common, due to seasonal variations in discharge.

Answer 115

It relates to the ideas and behaviours of society e.g. spiritual and religious inspiration, leisure and recreation opportunities like skiing, native people with distinctive cultures, scientific research like ice core analysis.

Answer 116

Biotic (living) and abiotic (non-living) things around us e.g. water cycling, climate control, carbon cycling, weather system control, fragile ecosystems, carbon sequestration (storage), genetic diversity.

Answer 117

-The land and waters support a fragile biodiversity of endemic plants, large mammals such as polar bears, reindeer, arctic foxes and whales, and a diverse range of fish and birds. These organisms and ecosystems are important opportunities for scientific research, wilderness recreation, cultural identity and economic exploitation. -The Greenland ice sheet contains about 10% of the total global ice mass and it therefore plays an important role in the global water cycle. -The average rate of ice loss from the Greenland ice sheet has increased from 34 gigatonnes per year between 1992 and 2001 to 215 gigatonnes per year between 2002 and 2012. This means that the Greenland ice sheet contributed 0.33 mm per year to global mean sea level rise between 1993 and 2010 and if the whole thing melted it's estimated to cause a global mean sea level rise of up to 7m. -Greenland also plays a vital role in regulating global climate via feedback cycles. Ice has high albedo which means it reflects more solar radiation than land. However, current ice loss in Greenland is reducing surface albedo, increasing the amount of solar energy absorded and further increasing air temperatures.

Answer 118

-Many Greenland Inuit now live in towns, with modern homes and appliances, and work in the growing mining and tourism industries, they still utilise the glacial and periglacial landscape to maintain their traditional lifestyle of hunting, fishing and herding. However Inuit hunting culture is increasingly threatened by pressure from environmental groups who have caused hunting limits for most species and the loss of sea ice is reducing the size of hunting grounds. However, there is an active movement among indigenous people to pass on their tradition. -Greenland ice posses immense value for scientific research as it contains a unique record of the Earth's climate history as it is made up of layers of snow and ice that formed over millions of years. The layers contaiin trapped gases, dust, pollen and water molecules that scientists can use to study past climates by drilling ice cores.

Answer 119

-Meltwater provides huge potential for hydroelectric power - the country is thought to have the world's biggest unexploited hydropower capacity. -As the ice retreats it is revealing high value deposits of oil, gas, metals and minerals, including rubies and gold. -Tourism also offers another area of economic growth for Greenland, with increasing numbers of cruise liners now operating in the island's western and southern waters during the peak summer tourism season.

Answer 120

-Climate change poses a significant threat to the natural glacial environment, as a result of ice loss and the opening up of areas for economic exploitation. -Increased industrial activity such as oil and gas exploration and marine shipping, bring stresses to the environment e.g. as the sea ice retreats, new commercial shipping routes could open in the Artcic such as the Northwest Passage connecting the Pacific and Atlantic Oceans. Increasing shipping increasing the risk of marine pollution. -Overfishing and the discharge of ballast water into Arctic seas may introduce invasive species that may outcompete and displace resident species. -A ban on radioactive and uranium mining was reversed meaning that areas in the south of Greenland could be opened up to large scale mining projects for uranium and rare earth metals. Radioactive waste from the mining process would endanger fisheries and farmland in the region which is vital fro local communities and is the only part of the island capable of sipporting farming. -Political disputes and conflict also threaten it as Russia claimed part of the Arctic seabed at the North Pole.

Answer 121

-The biodiversity of the tundra biome is low but it has global value, particularly for birds, as it provides a summer home of rmany migratory species and thus plays a role in worldwide food webs. -The permafrost also has global value as a large-scale carbon sink, storing an immense amount of carbon (2x as much as the atmosphere) and methane. In the warming climate, permafrost is expected to melt, and these stored gases will be released to add further warming.

Answer 122

-The Nenets' herder economy is driven by the reindeer meat they sell. Reindeer herding supports more than 10,000 nomads, who herd over 300,000 domesticated reindeer on the pastures of the Peninsula, 80% of which is privately owned by the herders -However, the economic value of reindeer herding cannot compete with the natural resources that lie beneath the pastures. -The Yamal Peninsula contains the biggest gas reserves on the planet, holding almost a quarter of the world's known gas reserves. There is now increasing investment and infrastructure development for large scale exploitation of this valuable energy resource.

Answer 123

-The Nenets' understanding of the harsh climate and fragile ecosystem has enabled them to live sustainably in this inhospitable land. -The reindeer provide the Nenets with transport, clothing, hides for tents, meat and income. The Nenets and their reindeer migrate seasonally to avoid the extreme cold winter temperatures in the north and to prevent the overgrazing of pastures.

Answer 124

-Climate change poses a significant threat to the tundra and to the Nenets. Earlier spring melts and delays to the autumn freeze are affecting the reindeers' and herders' ability to cross the frozen tundra. Large sinkholes were discovered which were believed to be caused by methane released as the permafrost thawed. -Early attempst to exploit the gas have posed considerable threats to both the natural environment and the Nenets. The infrastructure built to exploit gas has destroyed pasture, forcing overgrazing of the tundra and disruption to migration routes. -The area is now part of the 'Yamal megaproject' being developed by the energy gaint Gazprom. The aim is to exploit and bring to the market the vast natural gas reserves in the Peninsula. Several infrastructure projects are included, such as a 572km railway line, a gas pipeline and several bridges.These have already led to the eviction of 160+ reindeer herders. Many question whether the Nenets will be able to maintain their traditional culture, as these changes are forcing them into modern settlements and jobs.

Answer 125

-Mining or resource extraction e.g. gas, oil. -Tourism. -Farming e.g. in Alaska (periglacial) -Forestry. -Hydroelectricity.

Answer 126

-In developing countries, mountaineous regions suffer from limiations in transport links, access to essential supplies and markets and employment opportunities. In countries such as Nepal, Bolivia and Ethiopia, the highlands are largely inhabited by indigenous communities who gain their living from subsistence farming. -In Alpine areas in developing countries, the agriculture in upland glaciated regions is primarily pastoral because of the above-average precipitation, rugged terrain with steep slopes and stony, shallow soils, which make growing crops very difficult. In summer animals are grazed at high altitudes on Alpine meadows, which become free from snow and provide high quality grass and the grass in the valley bottom can be made into hay for winter feed.

Answer 127

-The tourist industry has seen a large increase in recent decades which has brought many economic benefits to mountainous regions with visitors attracted to the scenery of both present day and relicted glaciated landscapes. -A huge range of year-round, outdoor activities are possible in Alpine landscapes such as hill walking, climbing, mountaineering and skiing.

Answer 128

-Upland areas are being used increasingly for forestry due to the difficulty to use the land for hill farming. In the UK the main type of tree being non-native, quick growing conifers grown for softwod timber, wood pulp and paper. Conifers tolerate harsh climate and acidic soils that would not be suitable for other land uses.

Answer 129

-Glacial erosion plays an important role in removing regolith (loose overlying soil) and vegetation to expose economically valuable rocks. -In many active or relict areas there are mines and quarries of mineral deposits and ores. -In lowland areas, outwash deposits from the Pleistocene ice sheets provide a very important source of sand and gravel for the building industry, pre-sorted by meltwater into sands and gravels.

Answer 130

-Hydroelectric power (HEP) is a major use of water derived from glaciers. Both Noway and New Zealand derive over 90% of their electricity from this source.In most cases either a natural ribbon lake or a da and reservoir in a glacier valley provide HEP. -Switzerland has over 500 HEP stations producing 70% of its electricity. -HEP is a renewable 'green' source however ther are issues with reliability of water supply and environmental concerns over dammin rivers. -In mountain settlements in developing nations, such as Nepal and Bolivia, micro-hydros can revolutions the quality of life in many villages.

Answer 131

-Continuous cover of ground vegetation including sedges and mosses in the wtter hollows and scattered dwarf trees (elder and birches) on the lower ridges. -Elsewhere heaths, grasses and rapidly flowering plants flourish.

Answer 132

-Polar desert conditions prevail -However, a small range of plants survive in favourable sheltered location such as the purple saxifrage and the arctic poppy.

Answer 133

-The surface layer of permafrost melts to form bogs and shallow lakes. -These attract insects, which in turn attract migrating birds. -The tundra also supports a variety of larger animals such as the arctic fox, grey wolves snow geese and musk oxen.

Answer 134

-Temperatures fall well below freezing. -Plants - which many animals rely on for food - must survie under the snow to re-emerge and flow quickly once temperatures rise again in the spring.

Answer 135

-The Acrtic acts like a fridge by giving off more heat than it absorbs. Scientists are concerned that this process may be affected by three positive feedback loops, which are expected to worsen as climate changes. -The Arctic region is now working twice as fast as the global average through the albedo effect.

Answer 136

-As the extent of the white polar sea ice reduces, a smaller fraction of the sun's radiation is reflected back into space. More solar energy is then absorbed by the darker ice-free-water - raising temperatures that further reduce global ice cover. -When permafrost melts, it releases trapped carbon into the atmosphere as carbon dioxide and methane - thus increasing concentrations of greenhouse gases in the atmosphere. This in turn leads to increased global te,peratures and further melting. -Lower levels of snow cover increase areas of bare rock exposed to solar energy. Heat absorption from the sun then increases, leading to increased temperatures and snowmelt. Together, these three feedback loops exacerbate global warming.

Answer 137

14% Therefore the Arctic is known as a carbon sink meaning it absorbs more carbon than it releases. This happens because cold climate limits decomposition of orgnaic matter.

Answer 138

-As permafrost thaws, carbon could remain in the soil to be used by new vegetation which results in a negative feedback loop.

Answer 139

-Avalanches -Glacial outburst floods -Leisure and tourism -Reservoir construction -Urbanisation

Answer 140

-An avalanche exists where sheet stress exceeds sheer strength of a mass of snow located on a slope. -While avalanches tend to follow well-known tracks and can often be preditced, they are nevertheless a significant hazard, usually killing around 200 people per year with most of these deaths in the Alps and Rockies.

Answer 141

-A glacial outburst flood is a powerful flood caused by the sudden discharge of a subglacial or ice moraine dammed lake. -There is potential for an outburst whenever meltwater collects behind an ice or maine obstruction. -These very large floods are huge threat to people and property in inhabited mountain valleys.

Answer 142

-Resorts in glaciated regions, particulary ski resorts attracts large amounts of people each year, for example Zermatt in Switzerland attracts 2 million visitors per year. At the height of the ski season the resident population in Zermatt can be as high as 35,000. -This creates a huge demand for energy and water and threatens environmental degradation due to urbanisation, increase noise and vehicle emissions and expansions of ski areas.

Answer 143

-As glaciers store 69% of the world's fresh water, many countries are tapping into this source, especially due to fears of summer water shortages due to glacial retreat. -E.g. within the Chinese side of the Tibetan Plateau there are nearly 37,000 glaciers, containing the largest volume of ice outside the polar regions and also gicing birth to many rivers across Asia including Ganges. Almost 2 billion people more than a dozen countries depends on these ice fed rivers. -China aims to build 59 reservoirs to capture and save the glacial run off for the future. Reservour construction would require intense, heavy machinery and the clearing of land as well as irreversible damage to wildlife.

Answer 144

-Traditionally, the development of settlements in relict glaciated areas has been for agricultural purposes, however in polar environments this is not the case, -Settlements in polar regions tend to be surrounded by nothing and tend to be built for resoure exploitation purposes including whaling, mining and fishing. -Inevitably there are issues with pollution and toxic waste as well as conflicts occuring between these outsiders and the native people. -Regular contact from outsiders has reduced the chances of survival of traditional culture groups e.g. the Inuit in Greenland.

Answer 145

-Natural flora along some of the park's most famous peaks is being rapidly destroyed. -2 metre wide paths have become at least 12 metres wide due to social distancing -> a section of pathway of only 300 metres can cost nearly £45,000 to fix. -Visitors venturing off the track has also poses a new risk to wildlife in lesser-known parts. -The wear and tear of the pandemic due to pandemic walkers, and the increasingly severe weather due to climate change has increased the strain on those who look after the Lake District, which attracts 16 million tourists a year. -The erosion is taking its toll on local wildlife. Sediment washed off the hillside collects in lakes and rivers, reducing the breeding habitat for fish to lay their eggs and the variety of plants and insects meaning the area will attract fewer birds.

Answer 146

-The park receives around 100,000 visitors each year. -Deforestation in the local area to make lodges and firewood for tourists. -During the peak season, the park receives as many as 500 people per day making the hike to base camp, eroding footpaths. -Over 600 people attempt to summit Mount Everest every climbing season during the few weeks of the year when weather conditions are just right. For every climber there is at least one local worker who cooks, carries equipment and guides the expedition. -Each climber spends weeks on the mountain adjusting to the altitude at camps. During this time each person generates on average 8kg of trash and the majority of it is left on the mountain. -The slopes are littered with discarded empty oxygen canisters, abandoned tents, food containers and even human faeces. -Climate change is causing snow and ice to melt, exposing even more waste that has been covered for decades, trashing the natural environment and it poses a serious health risk to everyone who lives in the Everest watershed. -The parks watershed is an important water source for thousands of people living in local communities. There are no waste management or sanitation facilities in the area, so rubbish and sewage are emptied into big pits just outside of local villages where they wash into waterways during the monsoon season, spreading waterborne diseases such as cholera.

Answer 147

-Fix the Fells launches 20 years ago to repair "unsightly scars" to the landscape, including 30 metre wide gullies measuing 4 metres deep. -In the past two decacdes a small team of rangers have tended to 400 miles' worth of paths across the world heritage site and relies on donations and grants.

Answer 148

-Both government and nongovernmental organisations (NGOs) are attempting to clean up the mess on Mount Everest. -The Nepal government launched a campaign to clear 10,000kg of rubbish from the mountain. They also started a deposit initiative where anyone visiting Mount Everest has to pay a $4,000 deposit, and the money is refunded if the person returns with 8kg of rubbish. -The SPCC is an NGO and non-profit run by the local Sherpa people, who manage waste in the area surrounding Mount Everest, ensure that people have legal permission to climb and educate visitors on taking care of the environment. -The Mount Everest Biogas Project is also working to find a long-term, sustainable solution to the area's sanitation problem. They have plans to build a solar-powered system that would turn human waste into fuel for the local communties reducing the risk of water contamination and also creating more jobs.

Answer 149

-A receding glacier will produce more meltwater than normal. An increase in meltwater means a loss of steady supply in the future, which could have huge implications on rivers and populations relying on them. -An increase in meltwater could cause an increase in glacial outburst floods as deposited moraine can create glacial lakes whcih contue to increase in size until the moraine wall collapses, causing a catastrophic flood. -> Up to 15 million people face risk of catastrophic flooding from glacial lakes which could burst their natural dams at any moment and in Asia 1 million people live within just 10km of a glacial lake.

Answer 150

-Due to an increase in meltwater and the potential for more glacial outburst floods, river discharge will inevitably also be affected. -During the summer months where glacial ablation is at the highest during the year, meltwater and therefore discharge will increase - which will also increase sediment yield. An increased amount of sediment would mean water would increasingly become cloudy and sediment-laden, affecting the water quality.

Answer 151

People who are affected by or have an interest in something.

Answer 152

-Zermatt -National Parks in Canada (Mackenzie Delta) -Greenland

Answer 153

-The Alpine Treaty -The Antarctic Treaty

Answer 154

-Paris Agreement/COP21 -Kyoto Protocol -The Antarctic Treaty

Answer 155

-Came to force in 1961. -By 2015 there were 53 signatory nations. -It sets aside Antarctica as a scientific preserve, establishes freedom of scientific investigation and bans military activity on the continent. -The signatory nations meet regulary to review issues and add additional agreements or protocols, such as the Madrid Protocol, this protocl came into force in 1998, prohibiting any expoitation of Antarctic mineral resources for 50 years, except for scientific research. -This treaty one of the most successful international agreements and has allowed nations to peacefully cooperate to further scientific research and understanding of the Earth. -It recognises tourism as a legitimate activity in Antarctica and it regulates the industry, so bow tourism companies are required to have a permit to visit the continet and guidance is given to visitors so that they are aware of their responsibilties. -Commercial tousim using both ships and aircraft has increased steadily since the first commercial expeditions in the 1950s, and the total number of tourists visitng Antarctic peaked at around 46,000.

Answer 156

-It has lasted a long time. -Less greenhouse emissions (from not digging up or burning). -Protects effectively by strict rules. -No exploitation of the land. -Support from 60+ countries.

Answer 157

-Not all countries signed it. -Disagreements could occur. -More land claimed by some countries than others -> more pressure for these countries not to use their 'chunk' that they claimed with the intent to use it before the treaty. -Tourism still allowed, trust in travel companies and education of tourists on how to protect the area.

Answer 158

-International governmental organisations e.g. UNEP. -Transnational corporations e.g. Royal Dutch Shell, ExxonMobil. -Global, national and local pressure groups. -National and local governments. -Local businesses e.g. farming, fishing, ski hire. -Native peoples e.g. Inuit. -Tourists and visitors.

Answer 159

These organisations aim to promote international cooperation, including protection of the natural environment to achieve global sustainablity. For example, Antarctica is protected by an international treaty, written in 1959.

Answer 160

TNCs aim to utilise economic resources to maximise prodits and meet the needs of their shareholders, industries and consumers.

Answer 161

-Pressure groups try to influence public policy in interest of a particular cause. For example, conservationists such as Greenpeace, who campaign to protect fragile glacial landscapes from resource exploitation. -There are also groups who seek to change legislation to allow resource exploitation in protected areas .

Answer 162

These aim to establish appropriate management strategies to balance economic, social and environmental concerns to meet the needs of society. This can be very difficult to achieve where there are valuable economic resources in fragile natural environments, and therefore they must manage conflict.

Answer 163

These need to use local economic resources to maintain livelihood and quality of life, often in areas with few alternatives.

Answer 164

Often depend on natural environment for survival, including the provision of food, shelter, clothing and transport. Often nomadic, and traditionally migrate within a region, which may conflict with new stakeholders that move in. Have deep spiritual and cultural links with the physical environment.

Answer 165

Require infrastructure for travel and accommodation in order to enjoy the scenery, wildlife or recreational opportunities such as snow sports, whale-watching, trekking, climbing and birdwatching. Environment provides strong aesthetic value and appreciation of nature.

Answer 166

-It's an international treaty between the Alpine countries (Austria, France, Germany, Italy, Liechtenstein, Monaco, Slovenia and Switzerland) and the European Union. -The aim is to achieve sustainable development in the Alps by protecting the natural environment while promoting economic development. -The aim is to balance the needs of 14 million residents and 120 million tourists per year. -It entered into force in 1995 and consists of a number of protocols that provide specific measures required to achieve sustainability. Not all parties have ratified the protocols e.g. Switzerland has not ratified any protocols yet, which means that they have not passed national legislation to support the protocol. The Swiss government found that the convention was opposed by most of the mountain cantons (administrative divisions), which considered that responsibility for their local area would be taken out of their hands. They fear that the convetion focuses too much attention on protection of the environment and therefore threatens their livelihoods and economy.

Answer 167

-Combines multiple countries who are working towards the same goals. -Aims to create a balance between exploitation and protection. -Tackles climate change.

Answer 168

-Tourists still allowed to visit the area. -Not all countries gave ratified all of the protocols. -Disagreements between communities about the lack of responsibility they have.

Answer 169

-This active upland glacial landscape faces a number of human threats arising from its popularity as a ski resort, with over 2 million visitors per year. -Has a resident population of almost 600 people, which reaches more than 35,000 at the height of the ski season. This creates a huge demand for energy and water resources and threatens envrionmental degradation due to urbanisation, increased noise and vehicle emissions and the expansion of ski areas e.g. the preparation of pistes damages the fragile ecosystem and soil. -Zermatt markets itself as a sustainable ski resort, and both buildings and companies have won sustainability prizes. -The town is car-free, with tourists encourages to go on foot or use bikes, electric buses or electirc taxis. -Zermatt has 6 protected forests and 10 areas designated as wildlife sanctuaries, including 7 endemic plants. Legally enforced sanctuary areas are either closed entirely to the public during winter, or only designated routes may be used, with infringements punishable by law. -However, critics claim that there is still much more to be done to be sustainable, including limiting both the number of tourists and future construction. -In 2007 there was controversy over a proposal to build a tower on the Klein Matterhorn with a hotel and restaurant, to raise the mountain to over 4000 m in height. While this may have brought significant economic benefit to the tourist industry, envrionmentalists feared further degredation of the landscape.

Answer 170

-Care-free areas. -Use of renewable energy. -Water reused. -Wildlife sanctuaries. -Revegetating plants -> covering 85% of priority areas.

Answer 171

-Local scale. -Feared further degredation due to tourist numbers. -Conflict between tourists and local people.

Answer 172

-The Paris Agreement's central aim is to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2°c above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5°c. -It is a legally binding international treaty on climate change. -It was adopted by 196 parties at the UN Climate Change Conference (COP21) in Paris and was put into force on 4th December 2016. -It is a landmark in the multileteral climate change process because for the first tome a binding agreement brings al nation together to combat climate change and adapt to its effects. -It works on a 5 year cycle of increasingly ambitious climate change action. -More countries, regions, cities and companies are establishing carbon neutrality targets. -Zero carbon solutions are becoming competitive across economic sectors representing 25% of emissions. This trend is most niticeable in the power and transport sectors and has created many new business opportunities. -By 2030, zero carbon solutions could be competitive in sectors representing over 70% of global emission.

Answer 173

-The Kyoto Protocol was adopted on 11th December 1997. -It opertionalises the United Nations Framework Convention on Climate Change by committing industrialised countries and economies in transition to limit and reduce greenhouse gas emissions in accordance with agreed individual targets. -The convention only asks those countries to adopt policies and measures on mitigation and to report periodically. -Overall, these targets adds up to an average 5% emissions reduction compared to 1990 levels over the 5 year period 2008-2012. -On 8th December 2012 the Doha Amendment to the Kyoto Protocol was adopted for a second committment period 2013-2020. -During the second period, parties committed to reduce green house gas emissions to at least 18% below 1990 levels in the 8 year period. -An important element of the protocol is the establishment of flexible market mechanisms, which are based on the trade emissions permits. -The protocol also established a rigorous monitoring, review and verification system, as well as a compliance system to ensure transparency and hold parties to account. -The US dropped out of the protocol in 2001 as they believed that the agreement was unfair because it called only for industrialised nations to limit emissions reductions, and it felt that doing so would hurt the US economy. -Afghanistan was the 192nd and last signatory of the protocol in 2013.

Answer 174

-Freeze-Thaw Weathering. -Solifluction. -Nivation. -Frost Heave. -Groundwater Freezing. -Ground Contraction. -Aeolian Action. -Meltwater Erosion.

Answer 175

-When water freezes in the cracks and joints of rocks, it expands by up to 10% of its volume, weakening the rock and causing disintegration through repeated freeze-thaw cycles. This process is also known as frost action or frost shattering. -An accumulation of angular, frost-shattered rock fragments - known as blockfield when on a flat surface, and as scree when on a slope.

Answer 176

-The effect of the summer thaw on the active layer is to release a great deal of meltwater. As the water is unable to percolate downwards (as the ground is frozen), it saturates the soil, reducing the internal friction between particles, thus making it highly mobile. The lack of substantial vegetation to fix the saturated soil means that it begins to flow even on slopes of very few degrees. -A tongue-shaped feature at the foot of a slope - known as a solifluction lobe. These stepped lobes may be formed beneath a turf of vegetation which is pushed forwards and rolled under. Where vegetation is sparse stones heaved to the surfaces are pushed to the front of the advancing lobe and form a small stone bank at the front.

Answer 177

-Occurs mainly between north and east facing slopes beneath patches of snow in hollows of bare rock. -It is essentially frost action affecting the land beneath a blanket of snow and may involve a combination of processes weaking and eroding the ground beneath a snow patch. These processes include freeze-thaw weathering, solifluction and meltwater erosion. Freeze-thaw action causes the underlying rock to disintegrate. During the spring thaw, the weathered particles are moved downslopes by the meltwater and by solifluction. Over a period of time this leads to corrie formation. -Rounded nivation hollows formed in upland areas.

Answer 178

-This process results from the direct formation of ice crystals or lenses in the soil. On freezing, fine-grained soils expand unevenly upward to form small domes. As stones cool down faster than the surrounding soil, small amounts of moisture in the soil beneath the stone freeze and turn into ice, expanding by 9%. By repeated freezing and thawing over time, these crystals and lesnes heave stones upwards in the soil profile. -In areas where temperature fluctuate between 0 and -4°c the frost heaving and thawing is able to sort material into patterned ground. -On flat ground, stone polygons formed as the large stones settle around the edges of the domes; on slopes, stones stripes formed as the stones move downhill.

Answer 179

-Where water is able to filter down into the upper layers of the ground and freeze, where permafrost is thin or discontinuous, the expansion of the ice causes the overlying sediments to heave upwards into a dome, which may rise as high as 50m. -An ice-cored dome known as a pingo.

Answer 180

-When dry areas of the active layer refreeze, the ground contracts and cracks. Ice wedges will form when meltwater enters the crack during the summer and freezes at the start of winter. Repeated thawing and refreezing of the ice widens and deepends the crack, enlarging the ice wedges. -Large-scale polygonal patterns on the ground surface, known as ice-wedge polygons.

Answer 181

-Due to limited vegetation cover, the wind is able to pick up and transport the fine, dry sediment from the ground surface. -Extensive accumulations of wind-blown deposits, known as loess.

Answer 182

-During the short summer, thawing creates meltwater, which erodes stream or river channels. Refreezing at the onset of winter causes a reduction in discharge and sediment deposition in the channel. -Braided streams with multiple channels separated by islands of deposited material.

Answer 183

-Widespread in periglacial environments. -Develop in areas of continuous permafrost where the soils are poorly drained. -During the winter, soil temperatures drop below -15°c, causing the soil to contract and form cracks in the frozen ground. -When temperatures rise during spring, the soil expands and moisture collects in the cracks and freezes. -Freezing cuases the ice to expand and prevents the crack from closing. -The average dimension of wedge ranges from 15m to 40m. -Example: Long Hanborough Carrot near Oxford.

Answer 184

-As temperatures fall, there is progressive downwards freezing of water-saturated sediments. -Then, as subsurface pressure increases, it forces the ground to buldge upwards.

Answer 185

-Found in the Mackenzie delta, Canada. -Develop beneath laes that are surrounded by permafrost. -The soil beneath the central part of the lake is unfrozen as it is insulated by the water. -Sediments are washed into the lake, which slowly infills, continuing the insulation. -Over time, the water in the sediments freezes, but some trapped unfrozen material (talik) remains beneath this. -As temperatures continue to decrease, the permafrost encroaches on this unfrozen material; as it does, the pressure is increased due to water expanding on freezing. -To relieve the pressure, the surface bulges upwards. -Eventually all the water is converted to ice, forming a core of clear ice under the bulge.