Glaciers Flashcards
Long-term cause of climate change
Milankovitch cycle
Short term cause of climate change
Sunspots, volcanic emissions, asteroids
4 main types of cold environments
Polar, alpine, glacier, periglacial
What is a polar glacier?
frozen to bedrock and melting only occurs on the surface in summer months, occurs in polar glacial environments (move 2-3cm per day)
What is a temperate glacier?
temperature of the ice is close to zero and mild summer temperatures cause melting, occurs in alpine glacial environments (move 20-30cm per day)
Describe negative feedback
A lot of snowfall causes the glacier to advance meaning the snow enters the zone of ablation. More melting occurs to minimise the effects of more inputs, keeping the glacier balanced
Describe positive feedback
More snow means that there is an increase in albedo. This decreases the air temperature so accumulation rates increase.
Describe the Pressure Melting Point
The PMP is usually zero on the surface of a glacier, but it can decrease within a glacier due to pressure and the weight of the weight of the glacier.
How can a cold based glacier move?
Internal flow -ice crystals orientate themselves in the direction of ice flow, crystals slide past each other, slow process
How can a warm based glacier move by basal flow?
Higher temperature causes melting, friction is created causing more meltwater, glacier moves quickly
How can a warm based glacier move by creep?
Ice acts like plastic, pressure builds up causing ice to melt before the obstacle, water slips over the obstacle, pressure decreases so water freezes
How can a warm based glacier move by extending and compressing flow?
As ice flows over a gentle gradient it slows down and becomes thicker. As ice flows over a steeper gradient it flows and becomes thinner.
How can a warm based glacier move by surges?
Excessive meltwater underneath glaciers can trigger a sudden surge of movement. Only happens every 100 years.
What factors impact glacial movement?
Impermeable/permeable, temperature, rate of precipitation, gradient, thickness of ice and ablation
Name 4 erosional processes
Plucking/quarrying, glacial abrasion, glacial crushing and basal melting
What makes relict glacial environments high value?
Flat areas ==> farming (East Anglia)
Mountain range ==> HEP and tourism (Chamonix, France)
Valley ==> forestry (Snowdonia, Wales)
Name global climate change agreements?
Kyoto Protocol, Copenhagen, Paris Summits
Name national climate change agreements?
Alpine convention, Antartic treaty
Threats to cold environments
Greenland
what % of Greenland is covered in ice?
80%
What is the average ice loss in Greenland?
Ice loss rates have increased from 34 gigatonnes (1992-2001) per year to 215 gigatonnes (2002-2011) per year
What are the threats to Greenland?
Climate change
Increased shipping ==> pollution
Overfishing==>extinction of species
Political disputes over the artic seabed
Threats and solutions in Greenland?
Soil erosion=> farming problems=> (increased planting)
Trampling=>loss of biodiversity=>(limiting tourism)
Landslides=>infrastructure damage=>(afforestation)
Deforestation=>loss of habitats=> (education, regulations, afforestation)
Periglacial environment
Yamal, Peninsula, Russia
Threats to Yamal
Nenets forced into modern culture=> cultural dilution
Mining=> environmental issues
Global warming=>melting of permafrost=>flooding
Valuable National Park
Cairngorms, East Scotland
Why is Cairngorms valuable?
endangered species, glacial landforms (Old Ban rouche mountonne is 428m high), tourism
How much does tourism contribute to the economy in Cairngorms ?
30%
How is Cairngorms protected?
13 species protected by the European Protected Species Program, Forest Management (79% of trees are native) and Education
Glacial national park
Glacial National Park in Montana USA
What species are threatened in Montana?
Grizzly bears, only around 300 left
Threats to Montana national park?
Global warming=>glaciers melting=> endangered species=> (Rocky Mountain Climate Organisation)
Tourism=>trampling=> (93% of the park is managed)
How many tourists visit the Glacier national park per year?
2 million
Creating $1billion and 4000 jobs
