- Scientists could soon be hunting for icebergs off Antarctica to solve Cape Town’s water crisis.
- Only certain icebergs, that make up only 7% of the icebergs around the Antarctic, will be usable.
Scientists could soon be hunting for icebergs in Antarctica to solve Cape Town’s water crisis.
Among them is South African marine salvage expert Nick Sloane, who refloated the massive Costa Concordia wreck in the Mediterranean in 2013. Sloane says icebergs could fix a shortfall of around 100 million litres a day, at a cost of R1.6 billion ($130 million) for the proposed project.
Engineers and University of Cape Town academics have been assessing the project. Dr Chris von Holdt from the consulting engineering firm Aurecon, who has done a technical assessment and economic evaluation of the iceberg proposal, found it has "sufficient technical feasibility and economic merit to be considered seriously as a supply option for filling the supply gaps during periods of drought."
Scientists will be meeting in May to discuss the project. Here’s how it could work, according to the current proposal:
More than 2,000 billion tons of icebergs break off the Antarctic ice-shelf every year and drift with ocean currents until they melt in warmer water.
This is how much water Cape town uses in one year...
... and this is how big an iceberg would need to be to provide the required 135 million litres of water every single day for a year:
Scientists are looking for icebergs with steep sides and a flat top, with a thickness of between 200 and 250 metres.
An iceberg approximately this size would provide 50 million cubic meters of water - that's 135 million litres of water per day for a year.
Not just any iceberg will do.
Of some 271,000 icebergs, only 7% are suitable for harvesting, according to Norwegian glaciologist Dr Olav Orheim. Orheim will meet with other experts this month to investigate the feasibility of the proposal at a conference that is organised by Sloane.
Two tugs will encircle the iceberg, pulling an enormous piece of geotextile material around it as a "skirt" that reaches down the sides of the iceberg to below sea level.
Sloane wants to use some of the world’s most powerful tug boats - like the ALP Tug, which can pull 300 tonnes - to move the iceberg.
The ocean currents could also help push it towards South Africa.
Assuming the capture is done in a location westward of South Africa, the combined impact of the Circumpolar and the Benguela currents, as well as the Coriolis effect (the impact of Earth's rotation on weather patterns and ocean currents) may assist in reducing the towing power required.
It could then be parked 40km off the coast and turned into a mine.
The location is far enough off the coast to stay cool and can then be turned into a mine to be chopped into a slurry and melted into drinking water for locals.