Permafrost

Question 1

What is permafrost

Answer 1

Permanently frozen ground, not exceeding 0’C, in the summer months for at least 2 consecutive years

Question 2

Three types of permafrost

Answer 2

• Continuous Permafrost
• Discontinuous Permafrost
• Sporadic Permafrost

Question 3

Continuous Permafrost

Answer 3

Forms in coldest areas of world where mean annual air temperatures are below -6’C.

Can extend downwards from 100s of metres

Question 4

Discontinuous Permafrost

Answer 4

More fragmented and thinner

Question 5

Sporadic Permafrost

Answer 5

Occurs at margins of periglacial environments and usually very fragmented and only few metres thick

often occurs on shady hillside or beneath peat

Question 6

Factors effecting permafrost

Answer 6

Climate

Vegetation

Character of ground surface

Question 7

Factors effecting permafrost: Climate

Answer 7

main control

As temperature and amount of moisture available determine presence or absence, depth and extent of permafrost

Question 8

Factors effecting permafrost: Vegetation

Answer 8

cover can insulate ground from temperature extremes

Question 9

Factors effecting permafrost: Character of ground surface

Answer 9

different rock and soil types

Dark compact rocks absorb a greater amount of solar radiation

Question 10

What is active layer

Answer 10

Top layer of soil in permafrost environments that thaws during summer and freezes during winter

Question 11

What is Talik

Answer 11

Unfrozen ground