Ice On The Land Flashcards
(97 cards)
Environmental impacts of unreliable snowfall
40% less snow in the areas under 1000m above sea level over the last 50 years - led to greater pressure on high-altitude ski slopes, which are environmentally sensitive areas ( fragile alpine environments)
The chemical additives used in snow-making affect the natural vegetation
Why does deposition by glaciers occur?
When the ice carrying the material melts, the material is left behind on the valley floor
It also occurs when the glacier has reached its carrying capacity
How are drumlins formed?
A drumlin is an egg-shaped hill made from boulder clay (till). They usually occur together as a swarm
When the competence of the glacier is low, this encourages deposition of sediments
The melting glacier meets small obstacles which are enough to encourage deposition of boulder clay from the ice at the side of the obstacle, facing up-valley. This forms the stoss end
As the glacier continues to move, the boulder clay at the bottom of the glacier is moulded into shape around the obstacle. This forms the lee end.
Over time, the drumlin is re-shaped by further ice movements
What is subglacial moraine?
Material carried along the base of the glacier
What was the extent of maximum ice cover in the northern hemisphere during Pleistocene?
Around 20,000 years ago 30% of the Earth’s land surface was covered by ice
70m km3 of ice over North America, Europe and Asia
How are drumlins formed?
The competence of the glacier is low because it is filled with sediment which encourages deposition of sediment. Melting glaciers meet small obstacles and deposits boulder clay, creating the stoss end because ice deposits more sediment when facing up valley.
The glacier continues to move and the boulder clay moulded into shape around the obstacle, creating the lee end.
Some facts about the Athabasca glacier
6km long, 6km2 area, one of the most visited glaciers in the world because of its proximity to a major highway (Icefields Parkway)
What is the glacial budget?
It is the balance between accumulation and ablation in a glacier. Its determines whether the glacier will advance or retreat.
What are interglacial periods and how long do they last?
Warmer periods when the ice retreats to cover less of the Earth’s surface. Each one lasts around 10,000 years
Where are rates of abrasion highest?
Where there is a large amount of debris in the glacier
Where the ice is thick so there is more pressure
Where the rock debris is more resistant than the bedrock
What is the name given to the formation of glaciers?
Glaciation
What is an ice age, when was the last ice age called and when was it?
Ice ages are cold periods that last for millions of years when large masses of ice cover parts of the Earth’s surface Pleistocene that began around 2.6m years ago
What are adaption strategies in fragile environments?
Maintain ski tourism - artificial snow, develop on higher terrain, change slope design
Subsidies - annual or single government contributions.
Alternatives to ski tourism - non-snow related winter activities, all year tourism
Fatalism - carry on as usual or cancel ski tourism.
Economic impacts of glacial retreat
Lower ski resorts shutting down
Once a glacier has completely retreated, the amount of meltwater decreases - the industries that rely on the supply of meltwater e.g. agriculture for irrigation and HEP for electricity production, will make less money and could shut down
What are glacial periods and how long do they last?
Cooler periods when the ice advances to cover more of the Earth’s surface. Each one lasts about 100,000 years
Negative environmental impacts of Chamonix tourism
Large number of tourists cause a lot of traffic which increases pollution - a study from 2002 to 2004 showed that traffic pollution was worse in the Chamonix region than in the centre of Paris
Mountain footpath erosion
Farm animal gates left open - harm to animals
Litter can end up in the glacier - glass bottles are a safety hazard
A huge amount of energy is used to run the facilities for tourists e.g. the hotels, ski lifts and snow-making machines - increases CO2 emissions, which increases global warming
What is a glacier?
A glacier is a long standing mass of ice that moves very slowly downhill.
Economic impacts of unreliable snowfall
Making artificial snow, 15% of French ski resorts are covered by snow canons - in some resorts, making snow consumes more power than running ski lifts
If skiing is the main attraction, when there is too little snow it can be unsafe or not possible to ski. If there is too much snow, slopes are unstable increasing the possibility of an avalanche - both reduce tourists numbers
What is a long term glacial budget change?
Climate change (Ice ages, glacial and interglacial periods, etc.)
Positive social impacts of Chamonix tourism
Improvement in transport and health care
Job availability
Locals supplied with good facilities and activities
Clean, safe pedestrianised streets
Social impacts of glacial retreat
The Alps is the source of three main rivers of Europe; the Rhine, the Rhone and the Po. Glacial retreat will lead to unreliable freshwater supply to the region
Distributions to power supplies from HEP could leave some people with an unreliable power
If businesses shut down, local people will have to move away to find work
If an area’s population declines, local services and recreational facilities will also shut down
The ice will no longer be available for local people e.g. for trekking and ice climbing
Give some examples of natural causes of global temperature change.
The albedo effect means the whiteness of the surface of the earth. The white surface is (i.e. the more ice)The more sheet is reflected. The more the ice melts, the dark seawater will absorb heat instead causing the temperature to rise. Volcanic winter caused by Yellowstone volcano means ash will blackout the sun and cause global cooling.
Long term avalanche responses
Rules are stricter Skiers made to wear Avalanche transceiver Instructors warn skiers Rescue is free More equipment
Chamonix winter attractions
Skiing, snowboarding Mountain climbing Ice skating Sledging Spas Access to slopes via cog railways or cable cars Museums 60,000 tourists