Change is coming...
What will happen as temperatures rise?
Watch the movie for an introduction to some likely changes to the indigenous peoples of the area (Please note that this video clip also includes a short scene of whales being butchered.)
One of the most distinctive elements of the landscape of the far north is permafrost. This is frozen soil and bedrock, which underlies much of the land north of the Arctic Circle (and some areas further south) and produces a periglacial landscape.
The word 'permafrost' is perhaps a little misleading. It suggests that the ground is permanently frozen, whereas many areas have undergone periodic thawing and refreezing, and by definition, permafrost is ground that has been frozen for as few as one or two summers.
One of the signs of permafrost is that of leaning trees, and also leaning houses. Undulations in the ground surface happen because the thawing grounds settles unevenly. Permafrost creates challenges for people hoping to build in areas beyond the Arctic Circle.
There are different types of permafrost:
- Continuous: an area which is underlain by permafrost so that there are very few unfrozen areas
- Discontinuous: an area which is underlain by permafrost but has small areas of thawed ground, which might relate to south facing slopes or changes in the nature of the ground. Vegetation such as forests may also lead to areas remaining unfrozen.
- Sporadic: an area which is mostly unfrozen, but has occasional patches of frozen ground, perhaps related to the location of lake beds
Permafrost has an active layer: the top few inches which can thaw slightly during the summer months, releasing the ice as water. This slushy soil can then move downslope, sliding over the frozen ground below to create further landforms.
There is deep permafrost going down hundreds of metres. This can also include lenses of ice. As they thaw, the ground above subsides.
Infrastructure such as transport can be badly affected. The Baikal-Amur Mainline (BAM) railroad has suffered considerable damage through thawing. Imagine the problems facing long metal railway sitting on a thawing surface.
The study of permafrost unlocks a whole range of technical terms which may be unfamiliar. Many of them have Russian origins, as a lot of the work on permafrost landscapes was completed in that part of the world.
Tasks
Create a dictionary
Create a dictionary of terms and materials relating to permafrost and the features that are being created in the areas where it is found - some of the terms might be a bit unusual! Here are a few to start you off…
Design a house
Design a house that might be able to survive in permafrost areas. Remember that the heat from the house must not reach the ground or it will thaw out the soil.
You should also consider the cold temperatures, strong winds, long days in summer and long nights in winter, the need for services such as electricity, water and sewage to be provided, and the need to allow any snow accumulation to fall off the roof.
