The Yukon Geological Survey says chunks of ice have been falling and the cave is now posing a danger for hikers.
A unique, cave-like tunnel, left behind by a retreating glacier in Yukon has become a popular tourist attraction near Haines Junction, but it's no longer safe to enter and experts say it won't be long before it collapses.
The Kluane ice cave, just a short hike off the Alaska Highway, about 170 kilometres west of Whitehorse, has been attracting visitors for years but the Yukon Geological Survey is now warning adventurers not to walk under the huge, bluish ice arch.
Geologist Jeff Bond says the cave has shown serious instability in recent years and is now a hazard.
Slabs of ice weighing hundreds of kilograms routinely crash from the roof and Bond says that could be an indication of a structural shift caused by subterranean motion.
Experts believe the cave was carved by water flowing under what was once a massive glacier but the arch remained as the ice receded toward Mount Archibald and the Kluane ice fields leading to Mount Logan, Canada's highest peak.
Skiers and snowshoers were able to wander the length of the ice cave, especially in winter, but Bond says it will never be safe again.
"It will only become stable, I think, when it collapses and there is no more tunnel left," he says.
"When we visited it last year it was pretty apparent that there was ongoing ice collapsing off the ceiling within the tunnel throughout the winter and the summer."
The curious are urged to visit the impressive site, which spans a creek bed about 13 kilometres outside Haines Junction, but are reminded to stay well clear of the entrance because of the unpredictable conditions.
(The Canadian Press/CKRW)
(Below: an overview of the ice cave. Photo: Jeff Bond/Yukon Geological Survey)