The radar system installed Thursday on the Planpincieux glacier provides constant data on movements of ice even at the sub-millimeter level. That compares with the satellite photo monitoring already in place, which requires clear skies and takes between six to 12 days to get comparative images.
The mayor of the Italian town of Courmayeur, Stevano Miserocchi, has closed a mountain road and blocked access to nearby areas due to the risk that a 250,000-cubic-meter mass of the glacier could collapse into the Val Ferret, a popular hiking area. Experts say the melting has been linked to climate change, which moved the freezing point this summer to above the top of Mont Blanc, western Europe's highest summit.
Scientists and officials sounded the alarm after the glacier saw ice movements of up to 50 centimeters (20 inches) a day were recorded, due to the creation of a deep fissure during higher-than-usual summer temperatures. The movement has slowed to 10 centimeters (4 inches) a day in recent days.
The glacier itself spreads 1,327 square kilometers (512 square miles) across the Grande Jorasses mountain in the Mont Blanc massif, which straddles Italy, France and Switzerland. Climate change has contributed to a decrease in glacial mass throughout the Alps. A new special report by the Intergovernmental Panel on Climate Change this week said that glacier melt is happening faster than before and is accelerating.
The collapse of the unstable section of the Planpincieux glacier is not inevitable. But if it does fall all at once — the worst-case scenario — it's projected to reach the valley road that has been closed, said Fabrizio Troilo, a glaciologist with the Safe Mountain Foundation, which has been monitoring the Planpincieux glacier since 2012.
"We hope this big part of the glacier that is destabilized will fall down in smaller pieces," Troilo said, but added there was no way to forecast if it will happen as a single event or multiple smaller collapses. The mayor said it was also possible that no major break would happen, especially if the winter freeze arrives and stabilizes the glacier's movement.
Even though the road is opened up three times for residents, they are growing weary of the precaution. "I'd say this thing needs to fall. We are waiting for it to fall and we hope it will happen as fast as possible in order to save us all and free us from all this hassle," said Marco Belfrond, owner of the Miravalle hotel in Planpincieux, who has watched the glacier recede over the last 40 years.
Belfrond said his hotel wasn't at risk, but that the road closure was limiting the arrival of guests. "Thankfully it is low-season, so we don't have much movement. If it had happened in July or August, it would be much worse," he said.
Experts have ruled out using explosives to end the uncertainty. "Explosives on ice don't work well, and when the ice is fractured, it doesn't work at all. So, it would be a waste of time," Troilo explained.
Barry reported from Milan.