Study shows dramatic increase in meltwater from Canadian glaciers

15 Feb 2017 simond
Glacial moraine on the Queen Elizabeth Islands, Canada. Photo: John Sonntag, NASA

The ice loss from Canada’s Queen Elizabeth Islands glaciers has transformed them into a major contributor to sea level change, new research has found.

By combining ice discharge calculated from remote sensing data with the latest version of the Regional Atmospheric Climate Model, the study tracked the mass loss from the islands’ glaciers and ice caps from 1991 to 2015, providing a detailed partitioning of the mass loss over the past 25 years.

The researchers, from the University of California, Irvine, and the Jet Propulsion Laboratory in Pasadena, published their results today in the journal Environmental Research Letters.

Lead author Romain Millan, from UCI, said: “Our study provides crucial new information about the mass balance, and the role of the ice discharge in the mass loss, of the Queen Elizabeth Islands over the last 25 years.

“The mass balance of these glaciers and ice caps – essentially the gain and loss of ice from the glacier system – has been dominated by surface mass balance process, specifically surface melt for the last 10 years. However, our study revealed that, between 1991 and 2005, it was dominated by ice discharge.”

Despite the team’s ice discharge measurements almost doubling all available estimates for the region, they found that, after 2005, the overall impact of this was comparatively low, due to a significant increase in surface melt.

“After 2005, the ice discharge was only a major component in a few marine-terminating basins, where it doubled the ice loss,” said Mr Millan. “We also assessed that the large number of rapid and short-term increases in ice flow only had a minor impact on the long-term trend in ice discharge of these ice fields.”

The team found that after 2005, the mass loss increased markedly, transforming the QEI into a major contributor to sea level change.

Mr Millan said: “We identified meltwater runoff as the major contributor to these ice fields’ mass loss in recent years. With the ongoing, sustained, and rapid warming of the high Arctic, the mass loss of QEI is likely to continue to increase significantly in the coming decades.”