Cold environments – permafrost, tundra and fragile land
GeographySoils, Biosphere & EnvironmentAges 15–16
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Sign in to playA cross-section through tundra shows the active layer, permafrost, ice wedges and talik at the end of summer. Warm the climate, change the snow and the ground type, and put buildings (on the ground, on piles or on a gravel pad with thermosyphons), pipelines (buried or raised), roads, an open-pit mine or vehicle tracks on three plots; run the years to see thaw, subsidence, thermokarst ponds and damage. A tundra screen shows plant and animal adaptations and food links in summer and winter, and a world map shows cold, high-altitude and arid extreme environments.
Lesson: Cold environments: permafrost, the active layer and talik; tundra adaptations; human activity, damage and protection; distribution of extreme environments
What it shows
Permafrost is ground that stays at or below 0 °C for at least two years in a row; above it, the active layer thaws every summer. Much permafrost holds ice in wedges and lenses, so when it thaws the ground sinks, ponds form (thermokarst) and buildings, roads and pipelines can crack or break. Heat from buildings and warm pipes, stripping of vegetation and climate warming all deepen the thaw. Engineers keep the ground frozen with piles and air gaps, raised pipelines, thick gravel pads and thermosyphons. Tundra plants and animals are adapted to the cold, the wind and the short summer, and they recover slowly from damage.
How to use
In Permafrost cross-section, set the Mean annual air temperature, Climate warming ΔT, Winter snow depth and Ground type, choose a structure for each plot, then press Run or +10 years and watch the thaw, the table and the chart. Compare a heated building on the ground with one on piles. In Tundra life, switch between Summer and Winter and click organisms. In Extreme environments map, switch layers and click a region.
Parameters you can change
- Screen Permafrost cross-section, Tundra life, Extreme environments map
- Mean annual air temperature at the site -15–0 °C
- Climate warming ΔT 0–8 °C
- Winter snow depth 0.1–1 m
- Ground type Ice-rich silt, Peat over ice-rich silt, Ice-poor gravel
- Structure on the left plot Natural tundra, Heated building on the ground, Building on piles with an air gap, Building on a gravel pad with thermosyphons, Warm oil pipeline buried, Pipeline raised on supports with thermosyphons, Road on a thin gravel layer, Road on a thick gravel embankment, Open-pit mine, Vehicle tracks across the tundra
- Structure on the centre plot Natural tundra, Heated building on the ground, Building on piles with an air gap, Building on a gravel pad with thermosyphons, Warm oil pipeline buried, Pipeline raised on supports with thermosyphons, Road on a thin gravel layer, Road on a thick gravel embankment, Open-pit mine, Vehicle tracks across the tundra
- Structure on the right plot Natural tundra, Heated building on the ground, Building on piles with an air gap, Building on a gravel pad with thermosyphons, Warm oil pipeline buried, Pipeline raised on supports with thermosyphons, Road on a thin gravel layer, Road on a thick gravel embankment, Open-pit mine, Vehicle tracks across the tundra
Questions to explore
- Why does a heated building on the ground damage permafrost while a building on piles with an air gap does not?
- How do thermokarst ponds make thawing faster once they have formed?
- Which adaptations help Arctic plants and animals survive the long, cold winter?
