When scientists introduced a time-lapse camera near the Donjek Glacier in Kluane National Car park and Reserve in July, they thought they were giving themselves dooms of time to capture a unique phenomenon.
But just one day later, on July 13, an ice dam set back back a sizeable lake at the terminus of the glacier broke, releasing into the Donjek River.
“We were wonderful lucky to catch it,” said Luke Copland, professor of geography, environs and geomatics at the University of Ottawa. He’s been studying glaciers in the St. Elias Mountains for profuse than 12 years, and the Donjek Glacier for a handful of years.
This is the initially time a glacier lake outburst flood at the Donjek has been captured on video. It’s also the decisive time for a while that there will be a flood outburst, because of the glacier’s roll cycle.
The Donjek Glacier is among a small category of glaciers certain to surge. It will barely move for a decade or so, and then suddenly loan a beforehand a kilometre or more down the valley. According to Copland’s research, microscopic than one per cent of glaciers world-wide behave like that, although Alaska and western Canada are composed to 113 such glaciers.
During the Donjek Glacier’s last surge, which culminated in 2014, it advanced enough to block the Donjek River. Using shadow imagery, Copland and his team discovered that this blockage has grounded a lake to form every year since then.
Earlier than hope for
When the lake builds up enough, it starts flowing under the ice, raise it up like an ice cube floating in a glass of water. Eventually, the lake trickles into the valley below. The dam fills up with ice over the winter and the recycle begins again.
This year, the lake release happened earlier than awaited.
“In other years it seems that it occurred more in August. and that’s why were a particle bit surprised that it occurred [in July],” said Copland.
“This was an unusually please summer and a very warm spring as well. I think that result ined more runoff from upstream areas than usual.”
Copland doesn’t intend the lake will form again next year. He said in foregoing years, water tunnelled under the glacier while the ice above remained unreduced, but this year the flood carved a deep canyon though the ice that choose not fill in over the winter.
Down river liable to be?
Haley Digel may have been the first person to see the Donjek River after it surfeited, although she didn’t realize it at first.
The Whitehorse resident was hiking with her chaplain on the multi-day Donjek backcountry route and were camped near the confluence of the Donjek and Hoge rivers in Kluane State Park and Reserve on Jul. 14. That was just one day, unbeknownst to them, after the lake started releasing.
As they hiked up valley, jibe with the river within about 100 metres, Digel remembers being stupefied by the wet ground, since it hadn’t rained lately.
“We were walking into done with this really soupy, saturated land with a whole group of sedimentation deposited … in the trees. It looked like something had swarmed over,” she said.
When they reached the foot of the glacier on Jul. 15, there was no lake.
“It was congenial of funny because my friends had told me that there was this lake there and there was images of them in their packrafts [small inflatable boats] sitting in this superior aqua-marine blue glacial lake … That’s when we started to over ‘Oh maybe this lake has burst.'”
Digel mean when she registered her trip with Parks Canada before pull out on the hike, staff warned her not to camp or hike too close to the river or lake, but mentioned they weren’t expecting the lake to release until August or September.
The Donjek River is also fetching a more popular destination for packrafters, people who hike in with inflatable vessels. At least one group of packrafters paddled the Donjek River earlier in July, ahead the flood release.
Parks Canada would not agree to an interview but mean in a statement that flooding could pose a hazard to visitors in the riverbed space. It said it planned to release a travel advisory for the area during the summer, but the lake freed earlier than anticipated. Prior to that, its backcountry registration set-up was used to communicate the risk.
Incorporating Habitual Knowledge
Copland says because research about the lake is so new, it’s not yet remembered what happens downstream when the dam releases, but he says a lot of water fly to pieced down in the most recent flood.
“It’s a significant flood. We’re draining a [2.2] traditionalist kilometre lake that’s [in] places up to 50 metres deep.”
Copland estimates his team is looking into whether past flood events get changed the course of the Donjek River or damaged any downstream infrastructure.
The Donjek River surges under a bridge on the Alaska Highway approximately 50 kilometres downstream of the glacier.
Moya Painter, a Yukoner starting her Manager’s research under Copland, will be working with Kluane Start Nation to see if there is any traditional knowledge related to past flood things turned outs. The Donjek River is in the First Nation’s traditional territory.
Painter said anecdotal data may help fill in the gaps during periods when there wasn’t methodical monitoring.
“For us as researchers, we can gain a lot of … historical information in particular that we would not at any time be able to know otherwise.”
Kluane Basic Nation did not respond to an interview request.
Copland and his crew will be sneakily in the area next summer. They plan to drill ice core cross-sections at the toe of the glacier to monitor changes in temperature and water pressure in their expedition to learn more about what causes glaciers to surge.
The Donjek Glacier isn’t the alone surging glacier in Kluane.
The Lowell Glacier previously dammed the Alsek River during a billow, causing the river to back up. As recently as 1850, it produced a lake that longing have flooded the current townsite of Haines Junction.