Artic tundra and Alaska Flashcards
What underlies much of the tundra
Permafrost
How does the temperature of the tundra change with seasons
Summer months above freezing but rest is way below (can reach up to minus 40)
What are the main features of the water cycle in tundra
Low annual precipitation
Small atmospheric store of water
Limited transpiration (seasons)
Low evaporation
Limited groundwater and moisture stores
Accumulation of snow and ice during the winter
Extensive wetlands, ponds and lakes in the summer
Carbon cycle in the tundra
Permafrost is a vast sink (methane) Slow decomposition (due to temperature) Plants grow rapidly in the short summer
What is the productivity of tundra regions like
Poor
What are the problems associated with oil and gas production in Alaska (climate)
Harsh climate
The huge variations in temperature would cause the pipe to expand and contract
What was the solution to relieve the contraction and expansion of the pipe
Zig-zag configuration
What was the problem with the area that the oil and gas are in
Remoteness
The waters of prudhoe bay freeze so no tankers
What is the area prone to
Earthquakes
How did they solve the problems of the earthquakes
Pipe built on slider beams to allow for lateral movement
What are the problems with the ecosystem in Alaska
Fragile ecosystem (few links)
What was the problem with the permafrost for the pipe
It couldn’t be buried because the oil would melt the ice causing the pipe to sag
The freeze-thaw cycle would damage the pipeline
How did they solve the permafrost problems
Built the pipe line above ground
Refrigeration posts
Tapped in fibreglass insulation
Why did they build the pipeline
High global energy prices
US governments policy to reduce dependance on oil imports
War in the middle east
What impact does the pipeline have on the water and carbon cycle
Oil and gas exploration had impact on the permafrost and local water and carbon cycles
Damages ecosystem
Can upset the volume in stores
What are the management stratagies
Protect permafrost
Insulated ice and gravel pads
Buildings and pipelines elevated on piles
Drilling laterally beyond drilling platforms
Refrigerated supports
How much and where does it occupy?
8 million km2 in North Canada, Alaska and Siberia.
How long does it have a negative heat balance?
8-9 months.
What Is the biodiversity like in the south compared with the north
In the south vegetation covers all surfaces but in the north it becomes incontinuous.
What is the annual precipitation?
50-350 mm- vey low and mostly snow
Why is the atmosphere a small store of water
Very low temps reducing humidity.
Why is there low rates of evaporation?
Sun’s energy is used to melt the snow so ground temp is low and inhibits convection
What can permafrost cause?
Blockages of drainage creating extended wetlands,ponds and lakes in the summer.