oil and gas production in alaska impact on the water and carbon cycle(arctic tundra) Flashcards
where is Prudhoe Bay
on the North Slope of Alaska between the Brooks Range in the south and the Arctic Ocean in the north
when were oil and gas first discovered at Prudhoe Bay
1968
what were three fundamental challenges faced during the initial stages of development of oil and gas industries on the north slope
a harsh climate with extreme cold and long periods of darkness, remoteness and poor accessibility, and fragile wilderness of great ecological value
what drove production of oil and gas extraction in prudhoe bay
high energy prices and the US government’s policy to reduce dependence on oil exports
what seven infrastructure examples were introduced in which years
pipelines, roads, oil production plants, gas processing facilities, power lines, power generators and gravel quarries were completed during the 1970s and 80s
in the early 90s how much did the north slope contribute to the US’s domestic oil production
by the early 1990s the North Sope accounted for nearly 1/4 of the USAs domestic oil production
what proportion of the US’s domestic oil production does prudhoe bay account for today
6%
what does the decline of production in recent years reflect
high production costs on the north slope and massive growth of the oil shale industry in the USA
how has permafrost in the tundra been impacted by oil and gas extraction
permafrost is extremely sensitive to changes in the thermal balance, in many areas this balance has been disrupted resulting in the localised melting of permafrost
what are disruptions in the heat balance due to oil and gas extraction associated with
construction of oil and gas installations, settlements and infrastructure diffusing heat directly into the environment and the removal of vegetation cover which insulates the permafrost
what is the impact of melting permafrost on the carbon cycle
permafrost melting releases carbon and methane
what are the estimates losses per year of carbon from the permafrost
estimated C02 losses from melting losses vary from 7-40million tonnes per year
how else is C02 inputted into the atmosphere other than permafrost melting
glas flaring and oil spillages
how are photosynthesis and decomposition impacted by oil and gas production
the destruction of tundra vegetation reduces photosynthesis and the in turn uptake of C02, the thawing of soil increases microbial activity and decomposition, increasing emissions of C02
how does the slow growing nature of tundra vegetation worsen the impacts of oil and gas production
the slow growing nature of tundra vegetation means that regeneration and recovery from damage takes decades
how has melted permafrost impacted the water cycle
increases run off and river discharge, meaning that in summer wetlands, ponds and lakes are more extensive, increasing evaporation
what mining process creates artificial lakes and what effect does this have
strip mining of aggregates (sand and gravel) for construction creates artificial lakes which disrupt drainage and also expose the permafrost to further melting
how are drainage networks impacted
drainage networks are impacted by road construction and by seismic explosions used to prospect for oil and gas
what are four management strategies to moderate the impact on water and carbon cycles
insulated pads, elevated buildings and pipelines, lateral drilling and remote exploration
what are insulated pads
roads and buildings can be put on insulated pads to prevent heat diffusing to the permafrost below
how do elevated buildings and pipelines work
elevated infrastructure allows cool air to circulate beneath, preventing heat from being transferred to the ground and permafrost below.
what is lateral drilling
new drilling techniques allow oil and gas to be accessed several kms from the drilling site. with fewer sites needed, the impact on vegetation and permafrost is reduced.
how does remote exploration work
powerful computers can detect oil and gas, preventing the need for environmentally damaging exploration techniques such as seismic explosions.
