oil extraction in Alaska - periglacial case study

• describe the activity of oil extraction in Alaska (and Canada)

  - 33 million barrels of oil extracted from the Tar sands daily

  - Trans Alaskan Pipeline is 1300km long from Prudhoe Bay to Valdez, transports 1.4 million barrels a day

  - Arctic National Wildlife Refuge could contain over 16 billion barrels of oil, so pressure is on to drill this area for domestic use

  - 1960's US started drilling for oil in Alaska

  - Caribou babies born North, brought back down South. Areas must be preserved as caribou are a key way of life for Inuit tribes

  - Republican Party in US support and push for oil exploitation
• How new flows of material affected? (Carbon)


  - Release and burning of gas during drilling

  - Gases burnt in process called flaring release carbon dioxide

  - Methane is vented without burning

  - These greenhouse gases contribute to advanced global warming
• How new flows of material affected? (Gravel pads)

  - The loss of gravel from river systems alters the rate of transportation, deposition and erosion in the rivers

  - Report into gravel extraction from a glacial outwash aquifer near

  - Palmer found that ground water levels fell by more than a metre in the area extending over 2km from the site
• How are flows of energy affected? - Urban heat island effect

  - Urban heat island effect is when areas with densely populated humans have an increased temp compared to surrounding areas.

  - Production of heat from the extraction and transportation of oil can create urban heat island effect

  - Domestic heating systems in poorly insulated buildings contributes
• What is the impact of the urban heat island effect? (permafrost)

  - Heat released from drilling can lead to the thawing of permafrost.

  - Organic matter (dead animals & plants) frozen in permafrost is a potential major source of methane

  - As organic matter thaws it will decay releasing carbon dioxide and methane into the environment

  - Thawing of the permafrost has a detrimental impact on plants

  - Initially there is more water = rapid growth but as permafrost melts there is an impermeable layer that prevents drainage. In a few months there will be very little water

  - Increased subsidence and solifluction where businesses are situated
• Consequences of the urban heat island effect on the landscape? (thermokarst)

  - Thermokarst is formed by the thawing of ice on the ground

  - Removal of vegetation to allow for contraction or resource extractions removes insulation from the ground

  - Makes it more susceptible to thawing. A thicker active layer and subsidence is often created

  - North of Alaska subsidence rates average 3-4cm a yr

  - Building and pipelines transmit additional heat energy to the ground, speeds up formation of thermokarst