Glaciation Part 4 Flashcards

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1
Q

What is our case study for the peri-glacial landscape that is being used by people for resource extraction?

A

Oil extraction in Alaska

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2
Q

When were oil deposits first found along the Trans Alaskan Pipeline?

A

1968

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3
Q

What is the need for oil ?

A

USGS estimates that 30% of the undiscovered gas and 13% of oil are waiting to be found in the Arctic circle.
In 2014, 6.96 billion barrels of oil products were consumed. This is a concern to the American government as they want energy security.

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4
Q

What are the USA’s main crude oil imports?

A

Canada
Saudi Arabia
Mexico

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5
Q

What is the area 1002 in Alaska?

A

It is believed that here the area could contain 16 billion barrels of oil.
It is located NW in the Arctic National Wildlife Refuge.
An area of 6070km squared.
Only area that is protected currently from oil being extracted

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6
Q

What is the issue with drilling for oil in the area 1002 in Alaska?

A

There is permafrost present (80%) which contains lots of carbon, and so has huge impacts on climate change.

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7
Q

What are the reasons FOR drilling for oil in the area 1002?

A

The oil industry and government representatives. eg. Donald trump
Many Alaskan’s as they get money from the industry via the Alaska permanent fund.
Citizens of USA as they want security.

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8
Q

What are the reasons AGAINST drilling for oil in the area 1002?

A

There may only be a 50:50 chance of finding oil.
They would need to drill through the permafrost which causes release of carbon that’s not good for our atmosphere.

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9
Q

Where were oil deposits first found?

A

In Prudhoe Bay in North Alaska.
It has gone from a small settlement to a wealthy town.

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10
Q

How are issues being solved about the Trans Alaskan Pipeline in Alaska?

A

-The pipeline is raised above the ground to ensure that the permafrost isn’t going to melt and release carbon. As heat is being conducted into the ground.
Additionally with the pipe being raised animals, such as caribou, can migrate and travel underneath.
-As the pipeline goes through 3 mountain ranges it uses pump stations to move the oil along.
-

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11
Q

What are the impacts of oil extraction on material flows?

A

To establish permanent settlements, it is required for the oil industry to use careful engineering methods. As they can easily alter the thermal balance of the ground so prevent melting of the permafrost.
Buildings are also elevated above ground so that air can circulate and remove heat produced from the homes. They are built on gravel pads.

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12
Q

What are gravel pads?

A

Houses are built on them to allow air to circulate which removes heat. They are typically 1-2m thick and are made from sand and gravel.

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13
Q

Where is the gravel for gravel pads extracted from?

A

River beds. However, it alters the rate at which gravel is deposited and transported further downstream.

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14
Q

What are the two impacts of oil extraction of energy flows?

A

Release and burning of gas during drilling
Production of heat from extraction and transportation processes and associated infrastructure.

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15
Q

What does release and burning of gas during drilling mean on oil extraction?

A

The burning of gases is called ‘flaring’ which releases CO2.
It doesn’t directly impact the permafrost but contributes to climate change and global warming.

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16
Q

what are the impacts on landforms for the thawing of permafrost?

A

From the early 1980s, permafrost has warmed by 2 degrees and the active layer has been thickened by up to 90cm.
This is the case when construction of houses are built into the ground with no gravel pad, therefore heat will infiltrate into the ground so increases mobility of active layer also.

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17
Q

What is the landform that is created but the thawing of permafrost?

A

Solifluction lobes

18
Q

How are solifluction lobes formed?

A

Formed due to the downslope movement of water-saturated soil.
Where the surface layer melts it becomes more mobile as it is saturated by the impermeable permafrost below.
It is a slow process and can occur on slopes with a relief of 1-2 degrees.

19
Q

How much does a solifluction lobe usually move?

A

0.5- 5cm per year

20
Q

What is the impact on plants as a result of thawing of permafrost?

A

As there’s more water available there’s a rapid growth of plants, but as the permafrost melts there’s no impermeable layer to prevent drainage.
Therefore alters plants communities and the use by animals for food.

21
Q

What is thermokarst?

A

The process by which distinctive landforms result from the thawing of ground ice.
The landscape is dominated by extensive areas of hummocky ground with surface depressions.

22
Q

What are Alases?

A

A thermokarst landform that is large scale, flat floored, steep sided depressions.
They are formed by the thawing of ground ice and may contain lakes.

23
Q

What is our case study for the glacial landscape that is being used by people for hydro-electric power?

A

The Grande Dixence Dam in Switzerland.

24
Q

Where is the Grande Dixence Dam located?

A

At the head of the Val Des Dix valley in SW Switzerland.

25
Q

What is the size of the Grand Dixence Dam?

A

285m high, 200m wide and 15m at the base.
It is the tallest gravity dam in the world and the 5th largest dam in the world.

26
Q

When was the Grande Dixence Dam built?

A

1960s

27
Q

How much water does the Grande Dixence Dam store?

A

400 million metres cubed.

28
Q

Where does the water for the dam come from?

A

35 glaciers within the area.

29
Q

What is the lake behind the Grand Dixence Dam?

A

Lac Des Dix.

30
Q

How is the hydro-electric power produced?

A

Glacial meltwater is stored during the summer and then used to generate electricity during the high demand period of the winter. The water that’s stored in the land behind dam drives the turbines in 4 power stations.

31
Q

How many Swiss households does the hydroelectric power generate?

A

400,000

32
Q

What percentage of Swiss households energy is from fossil fuels?

A

Less than 5%

33
Q

How are Switzerland trying to minimise the impact of the Grande Dixence Dam ok the environment?

A

the pumping stations and power stations are largely built underground or concealed to retain aesthetics.
This is necessary to maintain an attractive environment for walkers, cyclists and hikers.
Tourisms has increased as a result of the dam. Tours are available.

34
Q

What is the impact on the glacial system of the Grande Dixence Dam?

A

Till at the bottom of the Dam.
The lack of flow of water stored behind dam means an energy loss which results to deposition of sediment behind the dam. Some water is used to flush out the sediment and move it downstream.

35
Q

What percentage of water is used for electricity generation for the Grande Dixence Dam?

A

85%

36
Q

What percentage of water is used to deal with sedimentation problems from the Grande Dixence Dam?

A

15%

37
Q

What’s the impact of river channels on the Grand Dixence Dam?

A

Increased channel erosion
Contraction in channel size
Risk of sudden flooding

38
Q

How is increased channel erosion occurring as an impact of the Grande Dixence Dam?

A

sediment is trapped behind the dam and the water that’s returned to the river channels above the dam has more energy so leads to more erosion.

39
Q

How is contraction in channel size occurring as an impact of the Grande Dixence Dam?

A

the lack of discharge in below dam rivers means that some virtually dry up in the summer.
The scale of contraction increases with distance downstream.

40
Q

What is the risk of sudden flooding as an impact of the Grande Dixence Dam?

A

In Val d’Herens (where the dam is situated) when excess stored water is to be released. It has an impact on tourists use/development along the valley floor.