Alaskan tundra

Question 1

Avg. temp below?

Answer 1

Below -15°C

Question 2

In winter when sun doesn’t rise, temps. can plunge below?

Answer 2

Below -40°C

Question 3

Biodiversity is low

Answer 3

Ecosystem is treeless

Question 4

Low annual precipitation

Answer 4

Less than 100mm, most is snow

Question 5

Limited transpiration due to…

Answer 5

Spareseness of vegetation

Question 6

Low rates of evaporation

Answer 6

Limited groundwater and soil moisture stores

Question 7

Accumulation of snow and river/lake ice during winter

Answer 7

Melting of snow, ice and upper active layer of permafrost in Spring

Question 8

Water stored as ground ice due to temperatures

Answer 8

Melts in summer and forms millions of pools and shallow lakes due to poor drainage - water cannot infiltrate below permafrost and ancient rock surface below tundra impedes drainage too

Question 9

Permafrost is a vast carbon sink full of decomposed plant remains

Answer 9

Permafrost contains 5 times more carbon than above ground biomass

Question 10

Carbon flux concentrated in summer as active layer thaws

Answer 10

Plants such as crowberries and moss grow rapidly due to long daylight hours

Question 11

Tundra plants input carbon rich litter onto soil which freezes and traps carbon in permafrost

Answer 11

Permafrost used to act as a carbon sink, but global warming could have caused it to become a carbon source

Question 12

NPP is low

Answer 12

Low temperatures and lack of liquid water limit plant growth

Question 13

Low temperatures and waterlogging do what?

Answer 13

Slow decomposition and flow of CO2 to the atmosphere

Question 14

Oil and gas discovered at Prudhoe Bay on North Slope in 1968

Answer 14

Oil and gas exploitation has had significant impacts on permafrost and local water/carbon cycles

Question 15

Melting of permafrost due to construction and operation of oil and gas installations directly heating environment…

Answer 15

Dust deposition darkening snow surface - snow absorbs more heat and removal of vegetation cover which insulates permafrost

Question 16

Estimated 7-40M tonnes of CO2 lost from Alaskan Tundra permafrost

Answer 16

Destruction of tundra vegetation reduces CO2 uptake

Question 17

CO2 emissions from North Slope alone increased 73% since 1975

Answer 17

Melting of snow cover and permafrost increases run-off increasing flood risk

Question 18

Strategies to protect permafrost: Roads built on insulating ice or gravel pads. Spine Road at Prudhoe bay lays on 2m deep gravel pad

Answer 18

Construct buildings and pipelines on piles, so cold air can circulate underneath and minimise heat transfer

Question 19

Drilling laterally from far away drilling sites with Shell snake drill - fewer drilling rigs needed

Answer 19

Refrigerated supports - used on Trans-Alaska pipeline to stabilise temperature of permafrost