Triglav Glacier on the brink of extinction

"After 80 years of measurements, we have reached a point where we are no longer merely monitoring the retreat of the Triglav Glacier, but its actual disappearance. Footage from recent weeks shows the very last patches of ice are disappearing before our very eyes," researcher Miha Pavšek from the Anton Melik Institute of Geography told the Slovenian Press Agency.

A combination of thin snow cover, its unusually early disappearance and exceptionally high summer temperatures will be decisive for the remaining ice.

"It's highly likely that by the end of the melting season we will be left without any ice in the area that we have known for generations as the Triglav Glacier," Pavšek said.

The Skuta Glacier, located below the mountain of the same name in the Kamnik-Savinja Alps, is following a similar trajectory. It is continuing to shrink and has broken up into several separate ice patches this year.

A winter with unusually little snow

This year's winter season brought particularly little snow. The maximum snow depth recorded at the Kredarica weather station below Mt Triglav was just 220 centimetres during the 2025-2026 season, compared with an average of 374 centimetres in the 1991-2020 period.

During that reference period, an average of around 1.5 metres of snow was still present at Kredarica on 1 June. This year 31 May was the last day with snow cover at the station.

As a result, the ice was exposed to direct melting unusually early and for a significantly longer period than in the past.

The retreat of both Slovenian glaciers is part of wider changes across the Alps, which are warming two to three times faster than the global average. Snow cover has declined in recent decades, snow melts earlier in spring, and the colder half of the year is increasingly interrupted by periods of above-freezing temperatures.

The median annual air temperature at Kredarica was generally below freezing between 1955 and 1999. Since 2011, it has been above freezing in ten years, and consistently since 2022.

Eight decades of evidence of retreat

The Triglav Glacier also illustrates the importance of long-term scientific observations.

"If we only had today's measurements, we'd conclude that there is very little ice left, but having eight decades of systematic measurements and documentation behind us, we can demonstrate the long-term trend of its retreat and link it to climate change," Matija Zorn, head of the Anton Melik Institute of Geography, says.

He adds that the value of this long-term research record will remain significant even after the glacier disappears from the surface.

Researchers have also recently obtained new data on the age of the ice in the Triglav and Skuta glaciers. They drilled ice cores and analysed their age using environmental tracers and isotopic methods.

The results, published in August as a preprint for publication in The Cryosphere scientific journal, show that the ice below a depth of one metre was more than 70 years old. The findings also suggest negative ice accumulation since the early 1960s.

Retreating ice preserves ancient history

The evidence left by the Triglav Glacier on the bedrock reaches much further back in time.

As the ice retreated, researchers discovered thin subglacial carbonate crusts on the freshly exposed, glacially eroded limestone. The crusts formed between the glacier and the bedrock and are between 1,000 and over 20,000 years old.

The oldest dates go back to the last glacial maximum. Because these thin carbonate crusts are exposed to dissolution and weathering once uncovered, their preservation strongly supports the interpretation that this part of the Triglav mountain range remained protected by ice for much of the Holocene.

"As the Triglav Glacier retreats, it reveals not only the bare bedrock but also a record of its much older history. The subglacial carbonate crusts formed beneath the ice, and their dates extend all the way back to the last ice age. These are very fragile formations that disintegrate rapidly if not covered by ice. Their age indicates that they were protected by ice for a very long time," explained Matej Lipar, head of the Department of Geosciences at the Institute of Geography.

As glaciers disappear, researchers turn to ice caves

Researchers have been systematically monitoring the Triglav Glacier for 80 years. When regular measurements began in 1946 its surface area was approximately 14 hectares.

The first official measurements of the Skuta Glacier followed in 1948, although unofficial observations had already been carried out two years earlier.

As surface ice bodies disappear, research attention is increasingly turning to high-altitude karst caves, where layers of permanent ice several metres thick have survived in some locations. There are more than 200 ice caves known in Slovenia.

The Institute of Geography is studying ice in selected caves as part of a research project attempting to reonstruct the Holocene climate using high-resolution cryosphere data from karst ice caves.

Key research sites include Snežna jama on Mt Raduha, Velika ledena jama in Paradana on the Trnovski Gozd plateau, Ivačičeva jama in the Triglav mountain range, and Ledena jama near the Viševnik mountain pasture in the vicinity of Mt Pršivec.

"Ice caves contain layers of ice several metres thick, which keep data on past climatic and environmental conditions. However, the volume of cave ice is also declining, so the time available for documenting, sampling and analysing it is limited. What we can still measure and preserve today may no longer exist in a few decades," says Jure Tičar, head of research projects on glaciers and ice caves at the Institute of Geography.

Source: The Slovenia Times/STA