Unit 6

Question 1

What is an example of glacial processes and landforms and landscapes on human activity?

Answer 1

Glacial Lake Outburst Floods (GLOF’s)

Question 2

What is a GLOF? Where and how does it form?

Answer 2

• can occur where a terminal/recessional moraine cats as a dam for glacial meltwater
• behind the moraine a proglacial lake will develop
• if the lake overtops the dam/dam gives way a torrent of floodwater and rock debris, cascade down the valley

Question 3

How many deaths are caused globally due to GLOF’s?

Answer 3

12,400

Question 4

What are the potential triggers for wave generation, that forms GLOF’s?

Answer 4

• earthquakes
• rapid input of meltwater
• icefall from hanging glaciers
• rock/snow/avalanches
• contact glacier calving

Question 5

What are some of the conditioning factors for dam failure (in terms of GLOF’s)?

Answer 5

• large lake volume
• low point in dam wall
• melting of buried ice in the moraine structure
• seismic activity

Question 6

What are the three key stages in GLOF formation?

Answer 6

1) formation of displacement waves in the lake
2) breach of dam/dam failure
3) resultant flood waves down-valley

Question 7

How does contact glacier calving trigger waves and dam failure of a GLOF?

Answer 7

large blocks of ice falls into lake displacing a large volume of water
this generates waves, which overtop the dam and flood down-stream

Question 8

How does rapid input of meltwater (supra, en, subglacial) trigger waves and dam failure of a GLOF?

Answer 8

the lake will overflow which then leads to dam failure, because it puts more pressure on it

Question 9

How does icefall from hanging glaciers/rock/snow/avalanches trigger waves and dam failure of a GLOF?

Answer 9

the impact from the rock hitting the water generates a ripple effect, creating waves

Question 10

How does seismic activity trigger waves and dam failure of a GLOF?

Answer 10

when the ground shakes, sediment will fall off, also generates waves, moving the water again

Question 11

How does large lake volume/low point in dam wall trigger waves and dam failure of a GLOF?

Answer 11

low point in dam wall = weaker and vulnerable
its easier for the water to move over the dam, weakening it

Question 12

How does melting of buried ice in the moraine structure trigger waves and dam failure in a GLOF?

Answer 12

if the ice, that holds the sediment together, melts then the sediment will weaken allowing water to push over the dam

Question 13

How might climate change lead to glacial lake outburst floods becoming more frequent in the future?

Answer 13

with temps increasing, the ice that holds the material together then the dams are more likely to topple over, more hazardous and more frequent

Question 14

What is the case study of a GLOF?

Answer 14

Lake Thorthormi, Bhutan, located in the eastern Himalayas

Question 15

How many potentially dangerous GLOF’s does Bhutan contain?

Answer 15

25

Question 16

Why is Lake Thorthormi, a very sever threat in Bhutan?

Answer 16

it is made up of numerous supraglacial ponds that have enlarged and become interconnected

Question 17

What area does Lake Thorthormi cover in Bhutan?

Answer 17

3.42km (squared)

Question 18

If Lake Thorthormi was to burst, how much water would be released?

Answer 18

53 million cubic meters

Question 19

How many people/buildings would be affected if Lake Thorthormi burst?

Answer 19

117 buildings impacted
362 people
5.22km of road

Question 20

How many hydro power projects could be destroyed if Lake Thorthormi burst?

Answer 20

3

Question 21

How have the glacial meltwaters in the area (Bhutan) benefitted the people who live in the local area?

Answer 21

• irrigation
• hydroelectricity

Question 22

In what year did a GLOF in Bhutan burst, and what the name?

Answer 22

1994 - Lugge Tsho GLOF

Question 23

How many people were killed in the GLOF burst in 1994?

Answer 23

24 people

Question 24

What was the name of the management strategy created to manage GLOF floods?

Answer 24

Lake Lowering

Question 25

What is the aim of Lake Lowering?

Answer 25

Enhances adaptive capacity to prevent climate change

Question 26

What were the socio-economic impacts from the 1994 Lugge Tsho GLOF?

Answer 26

- $10 a day given to those employed, to help with the removal of debris (5x the national average) - 250 temporary housing set up

Question 27

What are the socio-economic benefits of Lake Lowering, specific to Lake Thorthormi?

Answer 27

- contributes to local enterprise = 350 workers employed

Question 28

To what extent has the strategy worked, in Lake Thorthormi?

Answer 28

reduced the vulnerability, whilst providing people with employment

Question 29

What factors have hindered progress, in Lake Thorthormi?

Answer 29

requires manual labour can only work between July and October every year, only time its safe to work

Question 30

What is an example of human activity on glacial processes and landforms/landscapes?

Answer 30

Construction of reservoirs

Question 31

What is a reservoir?

Answer 31

a large natural or artificial lake used as a source of water supply

Question 32

Why are glacial troughs often ideal sites for constructing dams and reservoirs?

Answer 32

- U shaped, so all the water goes into the drainage basin - geology = all the water will have eroded soft rock, so all that is left is resistant rock - upland locations = higher levels of precipitation - glacial meltwater

Question 33

What are the arguments for reservoir construction in glaciated upland areas?

Answer 33

- without it people can't survive = reliable water supply - irrigation for crops - has kept flood water back - enhances environmental quality

Question 34

What are the arguments against reservoir construction in glaciated upland areas?

Answer 34

- requires large amount of land, could be used for economic gain = agriculture - requires significant funding (short term) - can cause microclimatic changes - inhibits migratory fish movements

Question 35

What is the case study for reservoirs?

Answer 35

The Elan Valley Reservoirs in Wales

Question 36

When were the Elan Valley Reservoirs built between and who built it?

Answer 36

between 1893 and 1904 by Birmingham City Council provide a source of clean, safe drinking water for growing pop and manufacturing industry

Question 37

Which two rivers were dammed to create the Elan Valley Reservoirs?

Answer 37

Elan and Claerwen

Question 38

Why was the location of the Elan Valley Reservoirs chosen?

Answer 38

chosen because of the high levels of orographic rainfall (1800mm annual)

Question 39

What is the geology around the Elan Valley Reservoirs?

Answer 39

narrow valleys = easy to dam impermeable rock = no infiltration allows large amounts of rainwater to collect and refill the reservoir

Question 40

How many people were relocated due to the construction of dams (Elan Valley) and how were they compensated?

Answer 40

over 100 relocated many receiving no compensation 18 farms also flooded

Question 41

What are the positive social impacts of constructing the Elan Valley Reservoirs?

Answer 41

- reliable source of water, hiking and fishing - job opportunities in construction

Question 42

What are the negative social impacts of constructing the Elan Valley Reservoirs?

Answer 42

-people relocated, with no compensation - 18 farms were flooded

Question 43

What are the positive environmental impacts of constructing the Elan Valley reservoir?

Answer 43

- 80% is environmentally protected area - leads to increase in biodiversity

Question 44

What are the negative environmental impacts of constructing the Elan Valley reservoir?

Answer 44

- 18 farms flooded, agricultural land

Question 45

What are the positive economic impacts of constructing the Elan Valley Reservoir?

Answer 45

- £6 million funding - 50,000 jobs

Question 46

What are sand and gravels quarried for? (extracted)

Answer 46

- road construction: mixing with asphalt - production of construction materials: concrete blocks, bricks and pipes -on icy roads in the winter - water filtration - glass making

Question 47

What is the case study for glacial sand and gravel extraction?

Answer 47

Wood Lane, Ellesmere, Shropshire

Question 48

What are the environmental negatives of sand and gravel extraction in Shropshire?

Answer 48

- traffic congestion from increased trucks - noise and dust - short term = deforestation = increased co2 emissions = land/ground pollution

Question 49

What are the economic negatives of sand and gravel extraction in Shropshire?

Answer 49

- reduction in potential material by 30% in 5 or 6 years of extraction - initial cost of setting up the quarry

Question 50

What are the environmental positives of sand and gravel extraction in Shropshire?

Answer 50

- increase biodiversity - 40 breeding bird species on the reserve - nesting opp, for sand martins (500 pairs known) - made on already derelict site

Question 51

What are the economic positives of sand and gravel extraction in Shropshire?

Answer 51

- more jobs for locals - boost local economy - can turn into reservoir or nature reserve (money)

Question 52

What are the social positives of sand and gravel extraction on Shropshire?

Answer 52

- better/more transport links - more houses built for growing population

Question 53

How is building and infrastructure an example of a human activity which directly causes permafrost melt?

Answer 53

- heating from houses transferred to the ground melting the permafrost

Question 54

What is the thaw-related damage to infrastructure in Alaska been estimated?

Answer 54

$35 million per year

Question 55

How is the Trans Alaskan pipeline an example of a direct cause of human activity melting permafrost?

Answer 55

oil extraction and transportation - raised 3m above ground - because pipeline temp is 80 degrees

Question 56

When was the trans Alaskan pipeline built and finished, how much did it cost?

Answer 56

Started March 1975, finished May 1977 $8 billion in construction

Question 57

How is the trans Alaskan pipeline managed, in terms of limiting the impacts to the permafrost in the region?

Answer 57

- elevated on thermosyphon piles (to keep the ground frozen) = $800 million

Question 58

What is an example of an indirect cause of melting permafrost?

Answer 58

Climate change (anthropogenic)

Question 59

Where is the case study for looking at how climate change has impacted the permafrost in the region?

Answer 59

Siberia

Question 60

What % of Russia's land surface contains permafrost?

Answer 60

70% of the land

Question 61

What is the average winter temperature in Siberia?

Answer 61

-34 degrees

Question 62

Is Siberia one of the fastest warming regions of the planet, how much permafrost is said to be lost by 2050 in this area?

Answer 62

Yes = fastest warming 1/3 of permafrost gone by 2050

Question 63

What are some of the environmental impacts of permafrost loss in Siberia?

Answer 63

- large amounts of methane released, lakes bubbling with methane - ground sinking, by 20 to 30% by 2050

Question 64

What are some of the social impacts of permafrost loss in Siberia?

Answer 64

12,000 died of starvation, due to damages to infrastructure such as roads

Question 65

What are some of the management strategies of permafrost loss in Siberia?

Answer 65

- buildings on stilts - elevating and insulating pipes

Question 65

Are permafrost regions carbon sinks or sources? Why?

Answer 65

carbon sinks - little to no decomposition

Question 66

How many more times potent is methane than carbon dioxide?

Answer 66

23x

Question 67

What does the IPCC stand for?

Answer 67

Inter-Governmental Panel for Climate Change

Question 67

How much have methane emissions from the arctic increased by between 203 and 2007?

Answer 67

31%

Question 68

What have the IPCC projected the temperature rise in permafrost regions to be by 2090?

Answer 68

10 degree increase

Question 69

What is the process of melting permafrost, due to global warming and release of methane accelerating warming known as?

Answer 69

positive feedback loop