A catastrophic rock-and-glacier collapse in Nepal is drawing attention to the risks posed by Canada’s own changing mountain landscapes, with a leading Canadian researcher warning that melting glaciers and thawing permafrost are creating new hazards. John Pomeroy, director of the Global Water Futures Observatories project at the University of Saskatchewan, said there is concern about similar types of mountain hazards occurring in Canada, which he says has more glaciers than any other country and vast areas of permafrost and snow. “All this is melting and it’s melting faster and faster every year,” said Pomeroy, who is also the UNESCO Chair in Mountain Water Sustainability. “So it’s creating new hazards that we haven’t seen before.” The warning comes a week after catastrophic flash floods swept through parts of Nepal and neighbouring Tibet. At least 1,100 people have been killed and thousands remain missing, including 30 Canadians. Search and rescue efforts continue as authorities grapple with the scale of the destruction. Pomeroy said the disaster began high in the Himalayas, where a massive collapse sent rock and a sizeable portion of glacier plunging roughly a kilometre into the valley below. He said the failure involved a slab of rock that had likely previously been frozen. When it fractured, the rock and glacier collapsed together, releasing vast amounts of meltwater stored in the ice. “This then formed, like a tsunami of water and ice and rock and sediment that, within minutes, ran downstream over the border station on the China-Nepal border,” Pomeroy said. It then “carried on at speeds over 160 km/h,” he said, with the wave reaching tens of metres high — “as high as 50 metres in some places.” Pomeroy said warming in the Himalayas has been particularly rapid in recent years, contributing to glacier retreat and thawing permafrost that can destabilize mountain slopes. Changing mountain environments While an event on the scale of the Nepal disaster is extreme, he said Canada has already experienced smaller examples of hazards involving changing mountain environments. In Jasper National Park in 2012, a rock-and-glacier collapse at Mount Edith Cavell sent a tsunami-like wave through the water below. “It was in the middle of the night, so nobody was there,” Pomeroy said. “If that had been in the afternoon, there could have been a thousand people.” Pomeroy also pointed to Canmore, Alta., as one of the mountain communities researchers are watching. The town, about 100 kilometres west of Calgary, sits at the base of steep mountain terrain. “We had the flood of a lifetime in 2013 and another pretty big flood — two floods in June this year involving debris movement in Cougar Creek,” Pomeroy said. “A lot of that debris comes out of solid ground in the upper Cougar Creek basin and thawing permafrost up there. And we’re getting more extreme rainfall events.” Pomeroy said a debris-control structure has since been built to help protect Cougar Creek, but added: “There’s many other mountain creeks around here that are very hazardous.” Those changes are also being noticed by people who spend their working lives in the mountains. Tim Ricci, director of operations with Yamnuska Mountain Adventures in Canmore, said changing conditions can be apparent over surprisingly short periods of time. “We spend so much time in this terrain and we see the effects of the change season to season, and sometimes week to week, given huge temperature fluctuations,” Ricci said. “As guides and mountain guides, we’re definitely adapting to those changes and thinking about how to best manage the risk side of things and safely move people through the mountains, given what we’re seeing with respect to climate change.” Another type of glacier-related threat has already forced Canadians from their homes. Near Pemberton, B.C., residents in the Poole Creek and Gates Lake area have experienced flooding for three years in a row, according to resident Nancy King. This year, residents were placed under an evacuation order over the threat of an outburst flood from Place Glacier. “What we know is that this is expected to be a yearly occurrence, as long as the glacier is still there,” King said. “As residents, the concern is, do we have to leave our home every year? Are we going to lose our home? What is it going to look like?” King said the uncertainty has taken a toll. “We all put a lot of value into our homes,” King said. “It’s intended to be our safe space and our safe haven. And it doesn’t feel that way.” Pomeroy said one of the challenges facing scientists is that many potentially hazardous areas are remote and difficult to continuously observe. He said the Nepal event was large enough to register as a seismic event and was initially interpreted as an earthquake. Six minutes later, he said, the flood wave reached the Nepal-China border. Pomeroy said better monitoring will be critical as mountain environments continue to change. “Our early warning systems have to go beyond stream gauging,” he said. “We need satellites, new satellites and repurposing of existing satellites to be monitoring high risk areas.”
