A cup of cold water, mate? Australian scientists develop methods for harvesting icebergs
As the worst heatwave in decades bakes the Western Hemisphere, Australian scientists may have a solution to the problem of dwindling fresh water supplies: iceberg harvesting. Ninety percent of the earth's fresh water lies locked in the icecap of Antarctica. If just 10 percent of the polar ice that slides into the sea each year could be towed back to civilization, the thirst of an urban population of 500 million could be met.
The idea of harvesting icebergs has been around for sometime. But the problem has always been one of melting. How do you get a giant iceberg to its destination before it dissolves into a small, uneconomical lump?
William Budd, a meteorology professor at the University of Melbourne, has been studying the melt rate of icebergs. He says the answer lies in enclosing the floating ice in a cylindrical container made of new high-strength synthetic fabrics such as Kevlar.
In other words, scoop the icebergs up with a lightweight fabric can open at both ends. Then, seal the ends, pump out the sea water, and tow it back to civilization. The melt rate is slowed considerably by the synthetic cocoon which also acts as a holding tank for the water upon arrival.
``A sealed container makes it possible to bring the water across the equator - to California or Saudi Arabia,'' Mr. Budd says.
The container envisioned would be 1 kilometer long and 100 meters in diameter. Budd downplays the engineering difficulties such a leviathan container might encounter. He says it could be taken to Antarctica on the deck of a ship and unfurled. ``Fisherman in Northern Australia use nets eight kilometers long and 20 meters across. There are a lot of operations of this scale.''
And the cost? Under $12 million, guesses Budd, perhaps less than $8 million (including synthetic fabric costs and charter fees for two conventional 20,000-horsepower icebreaker ships).
At that price, it could be a profitmaking venture, according to John Lovering, vice chancellor of Flinders University and head of Australia's Antarctic Scientific Advisory Committee.
Mr. Lovering calculates that just one of the ``very ordinary'' (500 meters by 250 meters by 250 meters) cubes floating about the Antarctic Ocean contains 15,630 million liters of high quality fresh water. Some areas of Australia pay .53 cents per 1,000 liters of excess water. At those prices, the garden-variety mammouth 'berg would be worth some $17 million.
Lovering's calculations are based on an iceberg deeper than Budd's container. But the estimate is valuable. Budd says further cost analysis is needed. But he believes this solution will be less costly than alternatives such as desalination or building dams.
Lovering says it's unlikely that iceberg harvesting would pose insurmountable problems under the Antarctic Treaty agreement. (The 1959 Antarctic Treaty made scientific research the continent's primary use, banned land claims, and outlawed military operations.) And, unless it became a widespread practice, would have negligible climatic impact.
The water authorities of Perth and Adelaide have shown interest in Budd's ideas. A proposal for a pilot project (one-tenth scale) may soon be submitted to Australia's Antarctic division.
Laments Budd, ``Apart from testing fabrics, the research is done. What we need now is an entrepreneur.''
But if an urban water authority hasn't the financial gumption, Budd notes that with a bit of savvy marketing, bottled water from the pristine environs of Antarctica could be big hit with the Perrier crowd.