Technology & Science

Klondike permafrost lives up to its name

Earth scientist in Alberta discovers permafrost in central Yukon survived warmer

Permafrost in some areas of the central Yukon never thawed out, surviving a warmer period in the Earth's history thousands of years ago, a researcher in Alberta has discovered.

For the first time in North America, results show deep permafrost remained frozen during the last warming period about 120,000 years ago, said University of Alberta earth science Prof. Duane Froese.

He sampled ice in the Klondike placer fields near Dawson City.

"The ice that we've just finished working up is about 200,000 years old," said Froese.

The sea level was higher then, and the tree line was further north.

Froese said the same kind of permafrost can be found in many parts of the western Arctic.

"Our permafrost is actually quite resilient, quite old through the western Arctic," he said. "It has survived periods in the past that [were] warmer than the present."

While the older deep permafrost is stable, Froese said people should still worry about how the top layer has been continuing to melt.