What is Periglacial?

• What is a Periglacial Landscape?

  A cold climate landscape next to an ice sheet
• During the last ice age, how much of the planet was considered periglacial?

  33%
• What are the typical temperatures of a periglacial environment?

  Daily temperatures are below 0 for roughly 9 months of the year, and highest average temperatures are between 1-4°c
• What is the typical average annual rainfall for a periglacial environment?

  below 150mm
• What is permafrost?

  Permanently frozen ground
• What are the 3 types of permafrost?

  Continuous, discontinuous and sporadic
• What is Continuous Permafrost?

  Permafrost near the arctic circle, where average temperatures are below -5°c. It extends downwards for hundred of metres
• How far down does the continuous permafrost in Siberia go?

  It may reach 1,500m down
• How far down does the continuous permafrost in North Canada extend?

  It may reach 700m
• What is Discontinuous permafrost?

  It’s found around 50°N, and it’s fragmented and thinner than continuous permafrost. It’s often found in ’islands’ of permafrost
• What is Sporadic Permafrost?

  Frozen ground found at the edge of periglacial environments where temperatures are slightly warmer, very fragmented and thin
• What type of permafrost is found in the Cairngorms in Scotland?

  Sporadic Permafrost
• What is the ‘active layer’?

  In summer, surface layers of frozen ground melt to form an active layer of wetland or saturated land
• How thick can the active layer of ground be?

  It ranges from a few centimetres to up to 5 meters
• What are the 5 periglacial processes?

  Frost heave, Ice contraction, Frost shattering, Nivation, Wind and Meltwater rivers