Extreme Environments Syllabus Ref • Mineral extraction. Periglacial areas: examine the opportunities and challenges posed by permafrost and other characteristics of periglacial areas for resource development (mineral extraction and any associated settlement and communications).
Challenges and Opportunities • To build the pipeline in such extreme conditions, several challenges had to be overcome. • On your handout match the problem to the solution
Problem - Permafrost • The oil must be heated in order to flow through the pipeline. It is 32 degrees when it reaches Valdez. Heat from the oil must not melt the permafrost, otherwise the ground will become boggy and could crack the pipe.
Solution 1 permafrost • The pipeline above the permafrost is raised above ground and a layer of gravel and insulation is placed beneath it to insulate the ground and prevent the permafrost from melting.
Problem - Expansion & Contraction • Alaska is cold in winter, but warm in summer. This and the heated oil, causes the pipeline to expand and contract and risk breaking
Solution – expansion & contraction • To allow for expansion and contraction, the pipe does not always travel in a straight line and instead zigzags to allow for sideways movement of the pipe.
Problem – Tundra Environment • There are many sensitive species of lichen and plants which can be easily damaged by vehicles. North of the Brooks Range there are treeless plains which are particularly susceptible
Tundra • There is a gravel road built alongside the pipeline, which vehicles must use to try to protect the surrounding environment
4. Mountains • Alaska is mountainous! • The Alaska range crosses the state
Mountains - solution • There are 12 pump stations along the pipeline to pump the oil up the mountains.
Rivers • The pipeline route crosses 34 rivers and over 800 streams
Rivers - solution • Across the largest river, the Yukon, a bridge has been built to carry the road and the pipeline. Across the smaller rivers and streams the pipeline is laid across them rather than buried.
Earthquakes • Valdez and southern Alaska are in an earthquake zone
Earthquakes - solution • The oil tanks at Valdez are designed to withstand major earthquakes up to 8.5 on the Richter scale. Theyare sited high above sea level so are not at risk from tsunami
Wildlife • Caribou migration routes cross the pipeline. Caribou do not like the man made pipeline
Wildlife - solution • Animals can move under the pipeline. Where migration routes cross, the pipeline is buried underground and insulated.
Exam qu • Examine the challenges presented in periglacial areas for mineral extraction. • 10 marks
Plan • You should include detail about the nature of the environment (ie it is extreme) • Clearly link the extreme conditions to difficulties • You should discuss oil extraction at Prudhoe Bay and the associated pipeline, transport routes, settlement at Deadhorse and Valdez