Pingo Research Paper

6) Explain the formation of a pingo including a couple of photos.*

Pingos are dome-shaped, isolated hills which interrupt the flat tundra plains. They have diameters of around 500 m and may be as much as 50 m in height. These occur in sand and therefore are not susceptible to frost-heaving. In open-system pingos, surface water infiltrates into upper layers of ground where it circulates in the sediments before freezing. This water freezes, expands and forms localized masses of ice and the ice forces overlying sediment upwards to a dome shape. In closed-system pingos, these form on small lakes where water is trapped from freezing above and from he advance of the permafrost. The water expands as it freezes, forcing the ground up into a dome

(i.e. the level of the permafrost table is lowered) – p.137

The ways that thermokarst can be increased include, the removal of mosses and other tundra vegetation for construction purposes. This allows more heat to be penetrated in the soil during the summer which increases depth of thaw. Also, the construction of centrally heated buildings warms the ground underneath and causes buildings to subside. Also, the sitting of oil, sewerage, and water pipes in active zones increases the rate of thaw, which causes the fracturing of pipes as the ground moves. Further, the drilling for oil and gas cause the heat from the drilling fluid melts the permafrost. Also, road construction upsets the equilibrium of slopes produced by solifluction.

b) Outline the ways how thermokarst can be decreased.

(i.e. the level of the permafrost table is raised) – p. 138

The ways that the thermokarst can be decreased include the construction of unheated buildings. This causes the upper surface of permafrost to rise and buildings tilt. Also, large, modern unheated buildings and airstrips are constructed on gravel pads because gravel is less immune to frost heaving and has less tendency to thaw underlying permafrost. Further, human attempts to exploit periglacial regions commercially try to balance short term economic gain and longer term environmental

Also, roads and airstrips are being built on gravel pads which are drained so that the ice cannot develop and frost levels will not alter. Further, cars in garages or parked outside are plugged into electricity supply to stop the battery from running and the petrol and oil from freezing. The roofs of buildings are steep which allow the snow to slide off and the building material is lightweight and wooden and the windows are triple glazed. Further, oil storage tanks are built on stilts which keep the oil heated and prevent it from freezing. Also, Utilidor, which are steel frames with aluminum panels heated by steam are used to prevent heating and protect fibrous