The Arctic Tundra Case Study
2.b. It is possible to identify the physical and human factors that affect the water and carbon cycles in an Arctic tundra area.
Case study of the Arctic tundra, including:
- Water and carbon cycles specific to Arctic tundra, including the rates of flow and distinct stores
- Physical factors affecting the flows and stores in the cycles, including temperature, rock permeability and porosity and relief
- Physical factors affecting the flows and stores in the carbon cycle, including temperature, vegetation, organic matter in soil and the mineral composition of rocks
- Seasonal changes in the water and carbon cycles in the Arctic tundra
- The impact of the developing oil and gas industry on the water and carbon cycles
- Management strategies used to moderate the impacts of the oil and gas industry
The location of the Arctic (latitude, Tree line & Isotherm).
Distribution of permafrost in the N. Hemisphere.
The tree line
As well as being the area within the Arctic Circle , the Arctic can also be defined as being the area where the average temperature for the warmest month (July) is below 10°C / 50°F.
An "isotherm" is a line drawn on a weather map or chart linking all points of equal or constant temperature.
This irregular and shifting July isotherm closely corresponds to the northern limit of tree growth and that varies both above and below the Arctic Circle.
As the warmer air at lower latitude s rises, the cold polar air rushes down to take its place. In the extreme cold winter temperatures , these blizzards carry ice crystals that destroy any vegetation that isn't low enough to hide under the snow during the winter months.
Just below the surface, the ground in this cold area remains frozen all year long, and the permafrost keeps trees from growing roots long enough to hold them upright.
Climate graph - skills test, interpreting and drawing a climate graph.
Rankin Inlet is found in North Canada in the Arctic.
Water and Carbon flows in the Arctic
Oil and Gas production and the impact on the water and carbon cycle - Case Study, Alaska
Key Idea: It is possible to identify the physical and human factors that affect the water and carbon cycles in an Arctic Tundra area.
- You must be able to:
- Describe and explain the impacts the developing oil and gas industry are having on the water and carbon cycle.
- Describe and explain the management strategies used to moderate the impacts of the oil and gas industry, including:
- Elevated buildings and pipelines
- Insulated pads
- Refrigerated supports
- Lateral drilling
- Remote exploration
- Arctic Council 2013
- Nature Reserves
- Polar Code 2017
- US Government banning
- the sale of drilling rights
Location - Alaska
The North slope of Alaska between the Brooks Range in the south and the Arctic Ocean in the north is a vast wilderness of Arctic tundra. Oil and gas were disovered here in Prudhoe Bay in 1968.
What is The Arctic National Wildlife Refuge (ANWR)?
The Arctic National Wildlife refuge (ANWR)
Physical Environment:
Where is the coastal plain?
Oil in the coastal plan.
- Prudhoe Bay near ANWR began oil production in 1977.
- Production peaked in 1988 at 2 million barrels a day but has since declined.
- The USA imports 3,500,000,000 barrels of oil per year and wants to become more self sufficient
- 4300 oil and gas exploration wells.
- Complex infrastructure of pipes, pumping stations, roads and bridges.
- Exploration only possible in winter when ground is frozen (January/February -30°C)
- Key is to prevent permafrost melting so must maintain vegetation (insulation) and protected from heat from buildings (elevated piling or gravel pads).
Impacts of the oil and gas industry - what are the main threats?
Using dual coding, summarise the impacts and the main threats of oil and gas industry from below.
On the land oil production will require miles of new roads (one estimate is 280 miles) new drilling pads, pipelines, pumping stations and airports. All these will damage the fragile arctic ecosystems, leading to a loss of habitat, fish and wildlife
The drilling pads would require massive quarrying of local rivers to produce gravel for construction sites, again leading to a loss of important riverine ecosystems. The quarrying would create huge holes in the landscape, as well as interfering with both the permafrost and the natural drainage systems.
Drilling creates about 40,000m3 of oily waste per well. This has to be disposed of so pits would need to be dug in the sands and gravels. However the waste may seep through the sand and into water supplies, as well as killing local fish and birds.
The area would produce over 50,000 tons of nitrous oxides which contribute to both acid rain and global warming.
Drilling on land would also force a change to the migration pattern of the massive caribou herds, leading to the potential loss of thousands of animals and again the livelihood of native peoples.
Other animals which would be severely disrupted by drilling activities are the polar bears. The Beaufort and Chukchi Seas together are known as the Polar Bear Seas and with the polar bears at Teshekpuk Lake these groups form over 20% of all the world’s polar bears. They would be forced to change their patterns of life, particularly with regards to feeding patterns and areas used to bear their young, with the large scale drilling operations.
Despite the environmental and ecological importance of the WAR the area has little protection because of the need to retain it as an area to be developed in an emergency. Since 1999 oil companies have been lobbying the Bureau of Land Management, which manages this area for leases to drill for oil and gas. A few “Special Areas” were established in places such as Teshekpuk Lake but these are now being largely ignored in the scramble by oil companies to gain leases on large areas for drilling.
As oil and gas resources in the nearby Prudhoe Bay development on Alaska’s North Slope start to decline, and as the price of oil rises to nearly $100 per barrel the oil industry is desperate to develop more resources on US soil. Now oil companies hold leases on over 80% of the WAR and are drilling test wells to establish if there are substantial deposits of oil and gas. Similarly Shell and other companies are keen to drill test wells offshore in the Beaufort Sea, the Chukchi Sea (Fig. 3) and the nearby Arctic National Wildlife Refuge (ANWR). The US Geological Survey estimates that there are 11.6 billion barrels of economically recoverable oil at $90 per barrel within the WAR. Americans currently use 7.2 billion barrels of oil per year, so all the oil in the WAR would only sustain the USA for about 18 months (and it would take the best part of 10 years before oil recovery started in earnest).
Which impacts do you think are the most significant on the water and carbon cycles and why.
Strategies to reduce the impact of development on the water and carbon cycles.
Managing the impacts to the Arctica (Buildings/pipelines elevated on...
Building and pipiles elevated on piles.
This allows cold air to circulate beneath these stuctures and provides insulation againat heat-generating buildinmgs, pipeowork etc which would otherwise melt in the permafrost.
Refrigerated supports
Used on the trans-alaska pipeline to stabilise the temperature of the permafrost.
Similar supports are used to conserve the permafrost beneath buildings and other infrastructure.
Insulated ice and gravel pads
Roads and other infrastructure features can be consructed on insulating ice and gravel pads, thus protecting the permafrost from melting.
Drilling laterally beyond drilling platforms.
New drilling techniques allow oil and gas to be accessed several Kms from the drilling site.
With fewer sites needed for drilling rigs, the impact on vegetation and the permafrost due to constructtin is greatly reduced.
More powerful computers can detect oil and gas bearing geological structures remotely.
Fewer exploration wells are needed which therefore reduced the impact onn the environment.
Alaska's Last Oil Documentary_031208
- 1. What is the impact of the oil industry on the local area?
- 2 How does this industry affect the water & carbon cycle?
3. How is climate affecting the local area?
