Canada’s Arctic glaciers said to be major contributor to sea level change


Researchers at University of California, Irvine, have published a study in the journal Environmental Research Letters wherein they have blamed Canada’s Arctic glaciers as being major contributor to sea level change.

With Canada holding 25 per cent of all Arctic ice, second only to Greenland, from 2005 to 2015, surface melt off ice caps and glaciers of the Queen Elizabeth Islands grew by an astonishing 900 per cent, from an average of three to 30 gigatonnes per year.

In the last decade, surface melt has been increasing dramatically owing to increase in air temperatures. Researchers found that overall ice mass declined markedly, turning the region into a major contributor to sea level change. The study provides the first long-term analysis of ice flow to the ocean, from 1991 to 2015.

The Canadian ice cap has glaciers on the move into the Arctic Ocean, Baffin Bay and Nares Strait. The researchers used satellite data and a regional climate model to tally the “balance” of total gain and loss each year, and the reasons why.

Because of the huge number of glaciers terminating in area marine basins, they expected that discharge into the sea caused by tide water hitting approaching glacier fronts would be the primary cause. In fact, they determined that until 2005, the ice loss was caused about equally by two factors: calving icebergs from glacier fronts into the ocean accounted for 52 per cent, and melting on glacier surfaces exposed to air contributed 48 per cent.

However, since then, as atmospheric temperatures have steadily climbed, surface melt now accounts for 90 per cent.
Millan said that in recent years ice discharge was only a major component in a few basins, and that even rapid, short term increases from these ice fields only had a minor impact on the long-term trend.