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The total volume is calculated to be an almost-unimaginable 158 cubic kilometres of water. That’s a cube of icy cold water almost 5.5 kilometres long, wide and high.
Many glacial lakes are located in thinly inhabited locales such as Greenland. Others are in places like the Himalayas, where they sit alongside villages and communities.
Canadian glacial lakes are swelling as well.
Their volume across the country, including those in the High Arctic, has increased about 20 per cent and they hold about 37 cubic kilometres of water, Shugar said. The lakes in British Columbia and Yukon have increased even more quickly, almost doubling in volume over the last 30 years to 21 cubic kilometres.
They can present a hazard. Because the water is only held back by ice, glacial lakes are prone to sudden events called glacial lake outburst floods.
“In western North America, the risks aren’t as high (as the Himalayas), but they certainly aren’t zero,” said Shugar.
And when they go, they go “absolutely gargantuan,” Shugar said.
In 1996, an outburst flood in Iceland created what was for a couple of days the second-biggest river in the world. A 1930s outburst from the Chong Khumdan glacier in the Karakoram range sent a wall of water, mud and debris nearly 26 metres high down the Indus River for about 1,500 kilometres.
Shugar said he’s not able to tell yet if GLOFs, as they are known, are becoming more frequent.
But he warns that water managers are going to have to keep an eye out for them as climate change continues to melt glaciers and fill lakes.
“Even here in the Rockies we may see increased development of these lakes,” Shugar said.
“This is an evolving hazardous landscape. This is something that needs to be constantly revisited.”
This report by The Canadian Press was first published Aug. 31, 2020
— By Bob Weber in Edmonton. Follow @row1960 on Twitter
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2020-08-31 15:03:25Z
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