Three years ago, the Serson Ice Shelf shrank from an area of 205 square kilometres to two remnant sections. This year, one of those sections was reduced from 42 square kilometres to 25 square kilometres, and other lost 80 per cent of its area, dropping from 35 square kilometres to seven square kilometres.

At the same time, the Ward Hunt Ice Shelf’s central area broke up into drifting ice masses, leaving two separate ice shelves with a combined area of 301 square kilometres, down from 340 square kilometres in 2010. ‘It has dramatically broken apart in two separate areas and there’s nothing in between now but water,’ said Luke Copland, a geographer at the University of Ottawa who co-authored the research.

The losses to the Ward Hunt Ice Shelf are particularly significant because it’s the largest and farthest north of the Canadian ice shelves and scientists believed that it would probably be the most stable.

According to Copland, since the end of July, ice equivalent to one and a half times the size of Manhattan Island has broken off, with the total loss of ice potentially reaching as much as three billion tonnes.

November 2011