3.4 - Thermokarst

Question 1

What is thermokarst?

Answer 1

• Permafrost

Question 2

What affect does an increase in temperatures in global temperatures mean for precipitation?

Answer 2

• increased evaporation
• more precipitation at ITCZ and Poles
• less at mid latitudes

Question 3

What changes are expected at the Arctic as a result of global climate change?

Answer 3

• Arctic ponds dry up
• increase in humidity
• increased melting of ice and permafrost
• more run off
• more local river flooding due to meltwater

Question 4

What changes are expected to the carbon cycle as a result of global climate change?

Answer 4

• CO₂ will be released from forest fires
• CH₄ will be released from wetlands, sea floor and permafrost
• Removal of carbon sinks and fires become a source of CO₂

Question 5

What is the Batakgiata crater?

Answer 5

• sinkhole opened up in 1960s in Yamal Peninsula in Siberia
  
  • due to melting of permafrost

Question 6

How large is the Batakgiata crater?

Answer 6

• 1km long
• 70m deep

Question 7

What affect does the growth of the Batakgiata crater have?

Answer 7

• trees sink, no longer shade permafrost
• damages pipelines
• swallows houses
• cracks pavements
• may release 50% of its stored methane in LT

Question 8

At what rate is the Batakgiata crater growing?

Answer 8

• 10m wider/yr

Question 9

How did the Batakgiata crater form?

Answer 9

• permafrost is melting in areas of thick tabular ice
• methane release is building up below unfrozen areas of permafrost
• pressure builds up and explodes
• crater is formed
• may fill up with water from further ice melt