Permafrost Thawing Behind Rockfalls in Italy’s Dolomites, Say Experts

“The entire summit is affected by an ongoing geomorphological process, likely linked to permafrost degradation,” the local geological service said following drone inspections on the slopes of Cima Falkner in the Brenta Dolomites in northern Italy.

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Nearly 100 tourists were evacuated after a series of rockfalls on a slope in the Brenta Dolomites in northern Italy, which experts have blamed on rising temperatures and permafrost thawing.

Local authorities are inspecting the slopes of Cima Falkner, where multiple rockfalls have been recorded since Monday, with the help of helicopters and drones. High resolution images of the slopes, collected using drones, show significant expansion of existing fractures, local media reported.

“The entire summit is affected by an ongoing geomorphological process, likely linked to permafrost degradation,” the geological service said, adding that many of these fractures, once filled with ice, now appear to be empty.

Numerous trails were closed and around 100 tourists evacuated from the area, with local authorities warning against visiting the area.

In a video posted on Instagram, Italian radio personality Giuseppe Cruciani, who was hiking in the area on Tuesday, described suddenly hearing a “tremendous boom,” followed by a series of rockfalls.

Volkmar Mair, Director of the local government’s Geology Department, said the situation in Brenta is not unique. “We have the same problems everywhere. We also had collapses in the South Tyrolean Dolomites and we are aware that we can have it everywhere,” he told local newspaper Corriere del Trentino.

Mair said that while the exact causes behind this event are not yet known, it was likely that it resulted from a combination of intense rains and temperature fluctuations as well as permafrost thaw.

Permafrost is a permanently frozen layer below the Earth’s surface, consisting of soil, gravel, and sand, usually bound together by ice. Rapidly rising temperatures are accelerating permafrost thaw in many regions across the world, with numerous studies indicating that without urgent action to curtail global warming, up to 93% of the world’s near-surface permafrost could disappear by 2100.

“When temperatures hover around freezing point, water freezes and expands. This expansion, where ice increases by 9%, exerts tremendous force – about 200 kilograms per square centimeter – leading to the fracturing of rocks,” explained Mair. In addition to the direct effects of thawing permafrost, which can trigger rockfalls, the frequent temperature fluctuations can cause the ice to transition states up to 10 times a day, said Mair. This continuous cycle acts like a wedge, gradually fracturing the rocks, resulting in sudden and substantial debris flows and “rock avalanches”.

Experts have repeatedly warned that rising temperatures are reshaping the iconic mountain range.

Last September, an assessment revealed that the Marmolada, the highest glacier of the Dolomites and an UNESCO World Heritage site, is disappearing at a rate of between seven and 10 centimeters a day and could melt away completely by as early as 2040. An ice avalanche on the glacier in 2022 killed 11 people and injured 8.

Globally, 68% of glaciers are set to disappear at the current global warming rate, with at least half of the loss taking place in the next 30 years, according to a 2023 study. 

According to Mair, nothing can currently stop glacial melting: “We should be cooling [the planet] besides halting planet-heating emissions. It will soon be impossible to go back and we will have to live with this [situation] for a long time.”

Featured image: Markus G. Klötzer, via Wikimedia Commons.