Climate change is causing Antarctic ice shelves to crack and melt.
Dr Craig Stevens from NIWA is recently back from the white continent where he led a team sampling the ocean water of the Ross Ice Shelf to see what's happening there.
But first they had to drill through 200 metres of ice.
The Ross Ice Shelf is the size of France, and the water beneath it is around twice the volume of the North Sea – or 2000 Lake Taupos if you prefer.
Dr Stevens says although little is known about it, recent measurements are alarming.
“This dramatic loss in sea ice that we saw last year, that’s some sort of signal - last year measurements went through the floor.”