Greenland Ice sheet could be losing mass, says study

A new study shows that global warming has reduced the mass of the Cordilleran Ice Sheet by half in as little as 500 years, indicating the Greenland Ice Sheet could face a similar fate.

A previous research had estimated that the Cordilleran Ice sheet covered much of western Canada as late as 12,500 years ago, but new data shows that large areas in the region were ice-free as early as 1,500 years earlier. This confirms that once ice sheets start to melt, they can do so very quickly.

Since, the Cordilleran Ice Sheet was similar in mass to the Greenland Ice Sheet, the researchers predict that the latter might have a fate similar to that of the former.

The melting of the Cordilleran Ice Sheet likely caused about 20 feet of sea level rise disrupting the "global conveyor belt" of ocean circulation and changing climate.

To conduct this study, researchers mapped and dated moraines (ridges along a glacier) throughout western Canada using beryllium-10.

A professor of physics in Purdue's College of Science, Marc Caffee said, "We have one group of beryllium-10 measurements, which is 14,000 years old, and another group, which is 11,500 years old, and the difference in these ages is statistically significant. The only way this would happen is if the ice in that area had completely gone away."

Around 14,000 years ago the Earth started warming, which led to melting of ice caps and thinning of ice sheets. About a thousand years later, the climate cooled again, and the glaciers that were melting started to advance. If the Cordilleran Ice Sheet had still been there when the climate started cooling then it would have been around now as well. This indicates a rapid disappearance rather than a gradual melting of the ice sheet.

"Continental ice sheets don't disappear in a simple, monolithic way - it's an extremely complicated process. The more we know about the retreat of the Cordilleran Ice Sheet, the better we'll be able to predict what's to come for the Greenland Ice Sheet," Caffee added.

This research was conducted in Purdue University's PRIME Lab.