Glaciation

Question 1

what is an example of a cold based glacier?

Answer 1

Meserve Glacier, Antarctica

Question 2

how do cold based glaciers move?

Answer 2

Internal deformation
- intergranular flow
- laminar flow

Question 3

how do warm based glaciers move?

Answer 3

Basal slippage
- regelation slip
- creep
- glacial surge

Question 4

what are the details of the cold based glacier?

Answer 4

• 7km long
• basal temp is -17C
• silt rich basal layer
• slow movement

Question 5

what is an example of a warm based glacier?

Answer 5

Athabasca Glacier, Canada

Question 6

what are the details of the warm based glacier

Answer 6

• move 2-3m a year
• 6km long
• 90-300m thick
• basal temp at PMP

Question 7

what is intergranular flow

Answer 7

when individual ice crystals re-orientate and move in relation to each other

Question 8

what is laminar flow

Answer 8

movement of individual ice layers within the glacier

Question 9

what is regelation slip?

Answer 9

Glacier melts to go over obstacle, then refreezes on other side due to pressure

Question 10

what is creep?

Answer 10

if ice encounters obsctale, its put under strain so deforms plastically and flows or creeps around the obstacle

Question 11

what is the case study of a landscape associated with the action of ice sheets?

Answer 11

Minnesota and the Laurentide ice sheet

Question 12

what is Minessota’s geology

Answer 12

• rocks lie in alternating belts of volcanic and sedimentary rock
• between these belts is granitic rock
• gneisses have been faulted to form some mountains

Question 13

how did the ice move across Minessota

Answer 13

• there were 4 lobes
• lobes advanced and retreated based on climate
• wadena lobe
• rainy and superior lobe
• des moines lobe

Question 14

how did the ice affect the geology of Minnesota

Answer 14

• origins of lobes resulted in till
• it transported and deposited this till as it advanced and retreated

Question 15

what was the erosional impact on the relief in Minnesota?

Answer 15

• as ice was sometimes 1km thick is wore down mountains
• now the highest peaks only 500-700km

Question 16

creating of lakes in minnesota?

Answer 16

• earlier tectonic tilting revealed weaker shales which are less resistant
• caused ellipsoidal basins

Question 17

what is the wadena lobe

Answer 17

• deposited drumlins and glacial drift
• till left the ground moraines with a reddish colour

Question 18

rainy and superior lobe

Answer 18

left behind coarse textured till with basalts, gabbro and red sandstone

Question 19

des moines lobe

Answer 19

till which is tan to buff coloured and clay rich

Question 20

what is minessotas pro glacial lake

Answer 20

• Lake Agassiz
• maximum covered 440,000km2 and in place it was 400m deep

Question 21

case study of a landscape shaped by the action of valley glaciers

Answer 21

Snowdonia

Question 22

when was Snowdonias glaciation at its extent

Answer 22

20,000 years ago

Question 23

U-Shaped valey in snowdonia

Answer 23

• Nant Ffrancon
• carved by an outlet valley

Question 24

what are snowdonias erosional features

Answer 24

• corrie
• aretes and pyramidal peaks
• truncated spurs
• hanging valleys
• roche moutonnee
• u shaped valley

Question 25

what are snowdonias depositional features

Answer 25

- tills and moraines - eskers - drumlins - kames

Question 26

what is the study of human activity in periglacial environments

Answer 26

trans Alaskan Pipeline

Question 27

details of the trans alaskan pipeline

Answer 27

- pump 1.4 million barrels - 1300km long with over 600m built on stilts

Question 28

what is the need for oil in alaska

Answer 28

- Alaska has 3 billion known barrels - they have no energy security

Question 29

what is area 1002

Answer 29

- contains over 16 billion barrels of oil so need to drill it to meet demands - 6070km in NW part of Arctic Refuge

Question 30

what are the support drilling into area 1002?

Answer 30

- oil industry supports - many alaskans get money from industry - $3000 per person - provide energy security

Question 31

reasosn against drilling area 1002

Answer 31

- some alaskans rely on Carabou and this would impact their migration - only 50% chance of actually finding oil

Question 32

solving problems with alaskan pipeline

Answer 32

- pipe is raised so no heat on permafrost - animals move below pipeline so migration routes not blocked - pipe is above river bed

Question 33

what is the impact of alaskan pipeline on glacial material flows

Answer 33

- permenant settlements alter thermal temp of ground - lead to thaw of permafrost - buildings are raised to remove heat

Question 34

what is the impact of alaskan pipeline on glacial energy flows

Answer 34

- release gas during drilling - release CO2 and methane which impact global warming

Question 35

effect of buildings in alaska on the permafrost

Answer 35

- have heating effect - lead to mobility of active layers and solifluction

Question 36

what is the methane problem in alaska

Answer 36

- organic matter frozen in permafrost is major source of methane - thawing leads to decomposition and released CO2 and methane

Question 37

what is the impact of alaskan pipeline on plants

Answer 37

- as more water is available there is rapid growth of plants - as permafrost melts, no impermeable layer to prevent drainage - after few motnhs, there is no water left.

Question 38

what is the cases study of human activity in glacial areas

Answer 38

Grande Dizence Scheme in Switzerland

Question 39

what are the details for Grande Dixence Scheme

Answer 39

- built in 1960s to provide hydroelectric power - cost of building was 1600million - hgihest gravity dam - 285m high

Question 40

what are the water details for grande dixence scheme

Answer 40

- stores of 400million m3 of water - water from area of 35km2 and meltwater from 35 glaciers - four pumping stations

Question 41

energy production for grande dixence scheme

Answer 41

- glacial meltwater is stored in summer and used for high demand power in winter - powers 400,000 homes

Question 42

what is the impact of the grande dixence scheme on the environment

Answer 42

- pumping stations are mianly underground - tourism has increased for helicopter rides - higher pollution from domestic sources

Question 43

impact of grande dixence scheme on glacial system

Answer 43

- 85% of water used for generation - 15% used for sediment problems - lack of water flow leads to deposition behind dam

Question 44

impact of grand dixence scheme of river channel

Answer 44

- increased channel erosion - contraction in channel size - risk of sudden flooding