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Oil Extraction in Alaska (Periglacial) - Coggle Diagram
Oil Extraction in Alaska (Periglacial)
The Alyeska Pipeline
1300km long
Transports 1.4 million barrels of oil a day
75% of it built on permafrost
Crosses over 4 major fault lines
Reserves
Government have permitted exploration of potential oil fields so demands from domestic sources can be met.
Extracting this oil means increased employment opportunities and use of the pipeline.
E.g. area 1002 in the Arctic National Wildlife Refuge contains over 16 billion barrels of oil - 6 billion of which could be extracted.
Impact on Periglacial Landscape System
Material flows can be affected through the
use of gravel pads
. Gravel is extracted from stream and river beds and used as an insulating base in road construction.The loss of gravel from river systems alters hydrological, depositional and erosional processes as well as the rate of transportation.
Energy flows are affected by the
release and burning of gas by drilling
. CO2 is released into the atmosphere and other gases like CH4 are vented. These are greenhouse gases.
Energy flows are also affected by the
production of heat from extraction and transportation processes
( and associated infrastructure). In Barrow, Alaska, mean temperatures were 2.2 degrees higher than the surrounding rural area. Heat from domestic systems in badly insulated building is a main contributor to this. Energy released into the environment by human activity affects geomorphic processes.
Changing Landforms
Heat released by buildings and infrastructure can lead to thawing of permafrost and a longer period of melting.
Building built directly on top of permafrost release heat energy into the ground which can cause subsidence and increase the mobility of the active layer. This can lead to solifluction.
Thermokarst
Alases may form (flat floored, steep sided depressions ranging from 5-50m in depth and 100m-15km in length) which develop from widespread thawing.
A landscape dominated by surface depressions due to the thawing of ground ice. Extensive areas of hummocky ground mixed with waterlogged hollows.
Depressions may fill with water to form shallow lakes (less than 5km deep and 1-2 km wide).
Thawing can be initiated by human activity like vegetation removal or by climate change.