Summer heat made a huge 'snow swamp' on a Yukon glacier

Melting on the Lowell Glacier in Kluane National Park could have repercussions for waterways and wildlife, says one glaciologist.

'To see this large an area form so quickly — I’ve never seen that before,' says glaciologist

The Lowell Glacier in Kluane National Park in August 2011. A stretch of hot weather this past July caused a lot of melting on the glacier, and the ice is not coming back, says a glaciologist. (Sean Kilpatrick/Reuters)

A heat wave earlier this summer caused some major melting of a glacier in Yukon, and one glaciologist says that could have repercussions for waterways and wildlife.

​In late July, Mauri Pelto was looking at satellite images of the Lowell Glacier in Kluane National Park when he spotted an enormous "snow swamp" — formed when meltwater mixes with snow to form a pool of slush — on top of the glacier.

Once that snow and ice melts, and runs off, it's not coming back.- Mauri Pelto, researcher with World Glacier Monitoring Service

Pelto, a researcher with the World Glacier Monitoring Service based in the U.S., routinely studies glaciers in Western Canada. 

He said the swamp was about 45 square kilometres in size, and it formed over just a few days.

"My first thought was, 'that's a huge snow swamp,'" he said.

"I've seen them before and I've encountered them on a glacier, but to see this large an area form so quickly — I've never seen that before."

Satellite images from July 22, top, and July 26 show a large area of meltwater form on the glacier. Light blue areas are frozen, while dark blue indicates areas that are mostly water. (NASA Earth Observatory)

Two satellite images tell the tale — an image from July 22 shows the particular area of the glacier frozen. The other image, just four days later, shows a large part of the same area covered with mostly water. 

According to Environment Canada, a community near the glacier, Haines Junction, Yukon, reached 29.3 C on July 22. That was the hottest July 22 on record for the area.

The following few days all saw temperatures in the high 20s, as well.

Repercussions 'for a long time'

Pelto said within weeks, water from the Lowell Glacier's snow swamp flowed off the glacier into Lowell Lake. He said that massive melt will have repercussions for the glacier "for a long time."

"It's not like a lake, where hot weather would warm up the water and cold weather would cool it back down. Once that snow and ice melts, and runs off, it's not coming back," he said.

Pelto said that means the Lowell Glacier has shrunk, and the impact will ultimately be seen in the streams fed by glacial meltwater.

"If your glacier shrinks, it's going to provide less water," he said.

"So, any of your late summer or fall runs of salmon on any of these streams that are glacier-fed — as the glacier shrinks, it's going to provide less meltwater runoff — and it should be a challenge for the salmon."

With files from Sandi Coleman