Jean-Louis Etienne
 
 
 
Jean-Louis Etienne - Alone on Ice pack
How man copes with the cold
 
Communications - Safety - Emergency assistance
 
Jean-Louis Etienne - Atmosphere & weather
The earth’s atmosphere  
 
Weather forecasting and modeling  
 
The climate and the north pole  
 
The solar energy balance  
 
The greenhouse effect  
 
Jean-Louis Etienne - Arctic ice
The ice pack: frozen saltwater  
 
Ice pack observation satellites  
 
Icebergs : frozen seawater  
 
The arctic ice: climate archives  
 
Ice ages and landscapes  
 
Jean-Louis Etienne - The ocean and marine life
The Arctic Ocean and the ocean currents  
 
Genesis of the arctic ocean  
 
Arctic plankton  
 
Oceanic biodiversity and the food chain  
 
Whales and other cetaceans  
 
Seals and walruses  
 
Jean-Louis Etienne - Life on land
Arctic flora  
 
Arctic fauna  
 
Polar bears  
 
Birds of the arctic  
 
Evolution of species and climate  
 
Jean-Louis Etienne - History and geography
Geography of the Arctic regions  
 
Geographic North Pole and magnetic North Pole  
 
Who owns the arctic ?  
 
Exploring the deep north  
 
The Inuit people  
 
The other peoples of the deep North  
 
The Arctic today  
 
Jean-Louis Etienne - Man's impact
Man and arctic biodiversity  
 
Pollution in the arctic  
 
Climate warming: the natural cycles  
 
The increase in the greenhouse effect  
 
The impact of global warming  
 
 
 
Arctic ice
Ice ages and landscapes
 
 

The Arctic regions: sitting on permafrost
Permafrost is the term given to frozen ground that never completely thaws in summer, sometimes remaining frozen as far as hundreds of metres down. The Arctic permafrost covers millions of square kilometres from Alaska to the northern reaches of Russia and China. In summer, because only the surface thaws and the deeper layers stay frozen, melt-water is not absorbed by the ground and it stagnates, creating vast marshland zones (wetland ecosystems).

A land frozen hard
When the ground in the Arctic freezes it contracts and splits in geometric patterns, often polygons. Where water has seeped into rocks, it expands when it freezes and splits the rock. Elsewhere, the rocks are worn by the incessant wind. Sometimes, ice expansion due to underground water freezing lifts up great stretches of ground, forming steep embankments that are quickly colonised by the Arctic vegetation in summer.

Landscapes shaped by the thaw too
In summer, the ground thaws but only on the surface. The water mingles with the surface layer forming mud that slides down the slightest slope. The thaw causes major erosion along the banks of rivers, lakes and even on the shores of the Arctic Ocean.

Bearing witness to past ice ages
Ice ages always leave traces on the landscape, and these physical traces can tell us much about the climate in the past. For example, glaciers deposit moraines, leave tell-tale scratches in the rock and carve U-shapes into lakes and valleys. Along coasts, geologists sometimes find fossilised terraces and beaches well above the present sea level, showing how the sea level has changed as ice ages came and went.

 

 

 
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