Will Deserts Drink Icebergs?
Victor, Paul-Emile, UNESCO Courier
Will deserts drink icebergs?
EVERY attempt has to be made to find further supplies of fresh water. There are two viable methods of doing this, and two only: the desalination of sea water, and the tapping of the only existing reserves of fresh water--the ice of the polar regions, formed by the accumulation and compression of snowfall over many thousands of years.
The desalination of sea water is expensive, whereas the production of fresh water by the transportation of icebergs is both economically competitive and feasible.
Icebergs are composed of fresh water so pure that it often approaches the characteristics of distilled water.
It has been estimated that the Antarctic icecap loses more than 10 million million cubic metres of ice every year in the form of icebergs, which eventually melt and disappear.
Why go to the South Pole to get icebergs? Why not the North Pole?
There are two reasons for this. First, most Arctic icebergs are irregularly shaped and dangerously unstable. Secondly, Arctic bergs come from mountain glaciers (from Greenland, for example) which precludes their ever being large enough. The "tabular' icebergs from Antarctica, on the other hand, are often big and regular in shape.
A "suitable' iceberg should be large enough (100 million tonnes) to provide the required amount of water by the time it arrives at its destination. It should be tabular, as regularly shaped as possible, and, to make towing easler, much longer than it is wide.
Icebergs of this type, always supposing that no internal or invisible cracks and stresses are subsequently detected, are formed in the Pacific sector, in the Atlantic sector, and in the Indian sector.
The most important problem will be to protect the icebergs against all types of erosion, such as melting, evaporation, mechanical erosion by waves, and friction caused by movement through the sea. …