Permafrost (or cryotic soil) refers to soil or bedrock that is constantly frozen over a long timescale. This timescale is a minimum of two years or more.[1]
Permafrost often contains ice within pore spaces and the changes in this ice impact the ground through the contraction and expansion processes, causing the ground beneath to move slowly.
The permafrost is in an area too cold for tree growth and usually marks the end of forest areas.
Distribution of permafrost
Permafrost includes the vast length of permanently frozen subsoil that is found in the extreme northern latitudes of Europe, Asia and North America.
Polar permafrost:
- Alaska
- Canada
- Northern Siberia
Alpine permafrost:
- Tibetan Plateau
- European Alps
- Rocky Mountains
Subsea permafrost
- Arctic Ocean
Melting of permafrost and climate change
Things to cover (for example):
- Measuring climate change with permafrost temperatures
- Problems noted with climate change impacts
- Seasonal features