$250k of equipment lost in ice berg break

Up to $250,000 worth of scientific equipment might have just been lost with a pair of massive ice bergs which have broken off the Nansen Ice Shelf. Photo / Craig Stevens

Up to $250,000 worth of scientific equipment might have just been lost with a pair of massive ice bergs which have broken off the Antarctic coastline.

Just as upsetting to the researchers which were using it is the prospect of also losing an entire year of crucial data, which was helping assess the subtle impacts of climate change on the frozen continent.

Scientists at the National Institute of Water and Atmosphere (NIWA) had attached an underwater mooring to the Nansen Ice Shelf at Terra Nova Bay, about 285 km from Scott Base, carrying a range of instruments that measured current, temperature and salinity.

But yesterday, NIWA oceanographer Dr Craig Stevens was monitoring satellite images when he spotted two separate ice bergs - each between five and 15km long as much as 100m thick - had broken off the ice shelf.

With them may have gone the mooring, which was into its second year of operation and was to be recovered early next year.

Another NIWA oceanographer, Dr Mike Williams, said the runaway ice bergs were so deep they could catch the top of the mooring and drag or break them if the icebergs drift over the mooring.

"We won't know until we go back next summer whether it is still there. We could lose a whole year of data. If that happens it will leave a gap in our research and that's unfortunate," he said.

"However, it is a risk we have to take -- we could see the crack from satellite images but predicting when an ice shelf will calve is difficult. It could have happened any time in the next five years."

The Nansen Ice Shelf, which is about 50km long and 30km wide, is among the many ice shelves that line the perimeter of Antarctica and regularly calve icebergs.

A small crack in the shelf was first spotted in December, 2013, and earlier this year, Nasa scientists noticed it had grown rapidly and had almost spread across the entire width of the ice shelf.

The mooring was deployed about 70m below Terra Nova Bay in December from the ice breaker ship Aaron as part of a collaborative programme between New Zealand and Korea.

Dr Williams said it contained current meters, temperature data loggers and instruments for measuring salinity which, altogether, cost between $200,000 and $250,000.

"We'll be watching where the ice bergs go via satellite and if we get lucky, they may go in another direction and away from where our moorings are."

The mooring is part of New Zealand's contribution to the Southern Ocean Observing System, an international consortium to better observe changes in the Southern Ocean.

A similar mooring, installed by the US is also at risk. However, another NIWA mooring stationed to the south should be safe from these icebergs.

The Koreans have a weather station now situated on one of the icebergs.