Scientists keep close eye on surging Canadian glacier

Researchers in Canada and the United States are closely watching the Alsek River, worried that a moving glacier nearby could block the river and potentially flood a village in Alaska.

An international team of scientists has set up a time-lapse camera overlooking the toe of the Tweedsmuir Glacier in northwestern B.C., which has been creeping toward the edge of the Alsek River for more than a year.

The most recent images from the camera, shown on the U.S. Geological Survey's website, show the glacier about 400 metres away from blocking off the river completely, possibly creating a flash flood toward the seasonal Alaska village of Dry Bay.

"The glacier has surged up to a kilometre in the last year, so there could be significant implications if the glacier advances suddenly in the next couple of months," Yukon government geologist Panya Lipovsky, a member of the international team, told CBC News.

"It's a pretty rapid rate of advance, considering that most other glaciers in southwestern Yukon are actually receding."

Late last month, Lipovsky and two other researchers flew to the Alsek River to change the orientation of the camera, which they had installed across the river from the glacier in August.

Additional sensors in the river will alert the scientific team to any rise in water levels.

Another glacier, the Lowell Glacier, surged about 200 years ago and blocked the Alsek River — about 50 kilometres upstream from the toe of the Tweedsmuir Glacier. The village at Dry Bay was destroyed when the ice dam the Lowell Glacier had created eventually broke.

There is no way to predict the glacier's next move, Lipovsky said. When the team visited it last month, "the glacier seemed to have quieted down a bit. It wasn't making any noise or showing any signs of actively surging," she said.

"Glacier surges aren't very well understood, which is one of the reasons why we're trying to study this one."