Case study - Alaska: Human activity and it's impact on periglacial environments - oil exploration in Alasa

Arguments for developing the area

Arguments for developing the area

-              Oil industry and some government reps

-              Many Alaskans get money from the Alaskan Permanent Fund - $3000 per person in 2012

-              Some think the USA need oil for security reasons – politically

Arguments against developing the area

-              Native Alaskans who rely on Caribou herds for their way of life

-              Small but growing Yukon/Alaskan tourist industry

-              Conservation groups

-              May only have a 50/50 chance of finding oil

Management of oil exploration/reducing the impact:

-              Pipeline raised above the ground and supported by refrigerants - to ensure heat is not conducted into the ground

-              Animals can move below the pipeline - to prevent blocking migration routes for caribou.

-              Pump stations move the oil along the pipeline - needed as got to get it over mountain range.

-              Pipeline is slung across rivers and not buried in the river bed.

-              Pipeline takes a zigzag route across the surface - to be able to adjust to ground movements

-              Oil storage tanks are raised up and built to withstand seismic movements

 

Impacts of oil exploration in Alaska on energy flows

 

1. The release and burning of gas during drilling -

Some gases are burnt in what is known as'flaring' - this is used to protect against the dangers of over pressurising industrial plant equipment. This releases large amounts of CO into the atmosphere.

These higher levels of carbon dioxide and methane contribute to global warming through enhancing the greenhouse effect - this can further raise temperatures with implications for permafrost.

 

2. The production of heat from extraction/transportation/infrastructure -

Town of Barrow in Alaska - numerous businesses provide support services to oil field operations & the village has grown due to the oil industry.

The buildings have produced an urban heat island effect with mean temperatures being on average 2.2°C higher than the surrounding rural areas.

Impacts of oil exploration in Alaska on the landforms/landscapes

-              Since the early 1980s, permafrost has warmed up by 2 degrees. Buildings and infrastructure release heat – this can lead to thawing of the permafrost and mean a longer period of melting the active layer.

-              Heat and subsequent melting of the active layer can increase the mobility of the active layer, resulting in gelifluction. This means that distinctive features such as gelifluction lobes may then form.

-              Gelifluction lobes form due to the downslope movement of water-saturated soil / regolith. When the surface layer melts in summer, it becomes mobile, and the whole mass of material moves downslope. This is a slow process – usually between 0.5-5cm a year.

ANWR / Area 1002

-              Located in the Arctic National Wildlife Refuge – however, the only part not to have protected wildlife designation

-              Could contain over 16 billion barrels of oil

-              The area is the key calving ground for the porcupine Caribou herd and the ANWR is the home to Alaska’s Gwich’in Indians and an abundance of wildlife.

-              There are concerns from environmentalists on the impact of drilling on fragile tundra soils (unique soils that are partially frozen year-round and are found in cold environments with short growing seasons and harsh winters. They store carbon,) and vegetation

-              Key issues is the presence of permafrost (which underlies 80% of Alaska) and the implications of oil extraction for this permafrost and the subsequent impacts.