Cold 3- Periglacial Landforms & People Flashcards
Periglacial areas
Areas that experience a cold climate, intense frost action and the development of permafrost
Either physically close to glacial or temporally close to glacial
Permafrost
Subsoil temperatures below 0°c for two years or more
Continuous, discontinuous and sporadic
Frost heave
Freezing of the soil just below the surface due to the direct formation of ice crystals of lenses in the active layer
Causes an upward expansion of the soil surface
Solifluction
The slumping or downslope movement of rock and soil material due to gravity
Saturated active layer is very mobile
Stone polygons
Patterned ground with rings of stone around raised domes
Formation of stone polygons
Frost heave causes upward expansion of soil
Ice lenses beneath large stones push the stones upwards as they freeze & expand
Solifluction lobes
Rounded, tongue-like features formed from solifluction
East Greenland Pingo
Water is forced upwards through a crack in the permafrost and freezes, creating a rounded hill
Makenzie pingo
A frozen lake with sediment on the floor insulates the ground beneath it, creating talik
The trapped water then freezes into a ball and raises the ground above it
Ice wedge polygon
Ground contraction creates cracks which then fill with water and freeze, exerting pressure and widening the crack
The ridges of the ice wedges create a polygon shape
Loess
Deposits of fine sediment are carried long distances by unobstructed winds at high velocities
Challenges of a cold environment for people
Very low temperatures, short summers, low precipitation, stony poor soils, permafrost, water logging, blizzards
Oil exploration in the Arctic
Prudhoe Bay oilfield discovered in 1967 Trans-Alaskan pipeline constructed (insulated stilts zig zag) Exxon Valdez (1989) ran aground & spilt 11 million gallons of crude oil
NPRA
National Petroleum Reserve, Alaska
An area that could be developed for oil fields ‘in an emergency’
ANWR
Arctic National Wildlife Refuge
Set up to preserve wildlife, continue subsistence uses and ensure necessary water quantity & quality
Under pressure to drill 1002 lands
Arguments for drilling
Enhance revenues to treasury, create 250,000 jobs, past developments didn’t seem to harm wildlife
Arguments against drilling
ANWR contains some of the last true wilderness, habitat to many species (Porcupine Caribou), claims that 2,000 km^2 of fragile tundra already destroyed in Prudhoe Bay (60 contaminated waste sites)
Alaska’s White Mountains
Sustainable tourism: network of routes, artificial soil protection sheets, drainage ditches, all hunters need permits, Rangers prevent illegal hunting
The Antarctic Treaty System
Prohibits any measures of a military nature, and provides the freedom of scientific investigation
It protects the environment, ensures waste is removed and tourist numbers limited
Sealing and whaling
Sealing around the Island of South Georgia, over 300,000 killed in three years
Blue and white whales targeted and stocks seriously depleted by 1965
International Whaling Convention
Ended whaling by 1985
Now there are thought to be over 5,000 blue whales
(Numbers dropped to 1,000 in 1967)
Fishing
Antarctic rock cod and krill fished
Krill underpins the whole ecosystem (sensitive to pollutants)
Quotas set to reduce fishing and restore stocks
Tourism in Antarctica
Increased from 9,000 in 1992 to 46,000 in 2008
20 tourists per expert guide & cruise ships of 100 people
Only 10m close to penguins & no litter
Only 5% of 200 landing sites showed damage
Concerns with Antarctic tourism
Extremely fragile ecosystem, disturb breeding animals, over-flying causes distress, invasive species brought into region
Madrid Protocol of 1998
Due to depletion of reserves in the rest of the world and the demand for resources, the mineral resources might one day have to be exploited (review in 2048)
