Mont Blanc and the Matterhorn are the most renowned mountains in the Alps, but, researchers say climate change is altering them remarkably, and the risk of falling rocks and moving glaciers is increasing.
"These days, it is no longer possible to stay in the spots where we used to set up our resting stops due to the danger of falling rocks. Any half apple-sized object can be fatal," said a mountain guide and researcher at Switzerland's ETH University.
"The mountains are constantly changing, but there is no doubt that larger rocks are increasingly falling," the researcher said.
The frozen layers melting from rocks and sediments that usually freeze throughout the year is one major reason of the threat.
Jeannette Noetzli, expert at the WSL Institute for Snow and Avalanche Research SLF, in Davos, said: "We see a clear warming tendency in the glaciers, especially since 2010."
And during the summer, the upper layers of the glaciers melt. "Obviously, the melting layer will get bigger," noted Noetzli.
In addition to melting glaciers, the melting ice drives the water to flow into cracks, creating enormous pressure that could violently break apart the rock masses, explained the researcher.