Two "massive" icebergs have broken off the Antarctic coastline, endangering valuable NIWA equipment used for research at a mooring deployed by New Zealand and Korea.
The icebergs, which broke off yesterday, are between 5km and 15km long, 5km wide and up to 100m thick. They were originally part of the Nansen Ice Shelf at Terra Nova Bay, about 285km from Scott Base.
NIWA scientists had been monitoring the area via satellite and first noticed a small crack in the shelf in December 2013. Earlier this year NASA scientists noted the crack had grown rapidly, spreading across almost the entire width of the shelf.
A NIWA mooring was deployed deep into the bay in December from the Korean ice breaker Aaron, as part of a collaborative programme between New Zealand and Korea. The mooring was into its second year of operation and contains valuable equipment that measures current, temperature and salinity.
That information is used to understand the effects of climate change on ice shelves and sea ice. There were plans to recover it early next year.
NIWA oceanographer Dr Mike Williams said the icebergs are so deep they could catch the top of the mooring and drag or break them.
"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.
"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. I could have happened any time in the next five years."
The mooring is part of New Zealand's contribution to the Southern Ocean Observing System, an international alliance to better observe changes in the Southern Ocean.
A mooring installed by the US is at risk too. Another NIWA mooring stationed to the south should be safe, however. Korea has a weather station, now on one of the icebergs.
