A one million dollar question for the experts: when will 250,000 cubic meters of ice break off from the Planpincieux glacier in the Italian Alps? It would take only 80 seconds for the equivalent of 100 Olympic swimming pools of frozen water to reach the valley floor.
Authorities say the nearby town of Courmayeur is not in danger. It’s too far away to be in the glacier’s shadow. But one local mountain road has been closed to protect anyone from venturing too close at the wrong moment, and some holiday homes have been deemed off limits.
We went up in a helicopter to see the glacier for ourselves, along with researcher Daniele Giordan, of the Italian National Research Council's Institute for Geo-Hydrological Protection. He knows this mountain better than most people, as he's been monitoring its movements since 2013. From above, the deep crevasse in the ice is obvious. It looks like a massive wall of concrete that's splitting apart. The slope of the mountainside is very steep, and the glacier is sliding downwards more quickly than usual helped in part by higher temperatures. Just below the crevasse is a steep drop off, and if the ice reaches that point, it could send that part of the glacier plunging down all at once.
Seeing the Planpincieux glacier from above is striking. You can see the size, and the problem it faces, much more clearly than when looking up from the valley below.
"So we are just in front of the final part of the Planpincieux glacier," Giordan said as the helicopter pulls into a hover over top of the crevasse.
"In front of us there is the most unstable area. We are closely monitoring it, to follow its evolution."
Giordan and his team built a solar powered monitoring lab on top of the mountain directly facing Planpincieux, with a commercial camera inside pointed at the glacier. It collects thousands of images every day, and relies on clear skies to work. The images are used comparatively, along with the data collected from a brand new radar system, installed just a few days ago on the valley floor. The two systems work together to provide near real-time updates on the movement of the ice. This is crucial information to scientists' understanding of the role climate change plays in the glacier's activity. It's also a warning system, so that experts can better predict when the ice will fall.
Giordan comes up regularly to make adjustments to the station and make sure it works properly.
"We chose this position because this is the best position to acquire a sequence of images," he said.
"Using this sequence of images, we are measuring the displacement, in particular the vertical component of the displacement of the glacier. The increase of temperatures during the summer season have a clear impact on this temperate glacier. In particular, there is a strong connection between the high temperatures, the ice melting, the amount of water inside the glacier and the glacier's activity."
According to a new daily bulletin that publishes the data collected, the glacier has been sliding downwards at an average speed of 35 to 40 centimetres per day. With colder temperatures coming up there’s the chance the glacier might stop moving for now. But the world’s long term forecast is warm, meaning the future of this glacier, and the others in the Alps is far from certain.