They’re far from the fastest things on water, but two massive icebergs are threatening to plough through Antarctic research gear and destroy a year’s worth of data, scientists say.

Researchers from New Zealand’s National Institute of Water and Atmospheric Research say the two huge hunks of ice, which could be up to 15km across and more than 100 metres thick, have broken off the Antarctic coastline over the weekend and may now be on a crash course with mooring containing precious equipment.

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The gear was left there by New Zealand and Korean research teams over a year ago and contains highly valuable devices for tracking current, temperature and water salinity as part of climate change research.

The size and depth of the icebergs means they could catch the top of the mooring as they drift past.

But NIWA oceanographer Mike Williams said whether the gear survived wouldn’t be known until summer.

“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.

A similar mooring installed by US researchers is also at risk, NIWA says.