Snow, glaciers and permafrost are of great importance for Switzerland. Their changes are documented by detailed measurements. This web portal shows and explains selected long-term measurement series of the cryosphere.more

Image: NASA Earth Observatory, Jesse Allen and Robert Simmonmore

Severe melting of glaciers despite heavy snowfall at high altitudes

After the extreme circumstances encountered in 2022 and 2023, no relief is in sight for Swiss glaciers. Despite exceptionally large volumes of snow during the winter, a combination of temperatures in July and August that at times reached record levels and dust from the Sahara resulted in a loss of 2.5% of the glacier volume. This was reported by the Swiss Commission for Cryosphere Observation of the Swiss Academy of Sciences on Tuesday.

Large volumes of dust from the Sahara entered Switzerland in several waves in the winter and spring of 2024. The dust collected on the surface of the snow and glaciers, leading to an increase in solar radiation absorbed during the summer. This considerably accelerated the thawing process.
Image: Matthias Huss

When it comes to glaciers, the year 2024 was notable for marked contrasts. Swiss glaciers enjoyed extremely favourable conditions up to and into June, thanks to 30% more winter snow than the average and an early summer marked by rainfall. However, the dust from the Sahara – which covered the surface of the snow – accelerated the melting process, and August saw the greatest loss of ice recorded since measurements began. Overall, the glaciers also experienced melting of a striking degree in 2024, as illustrated by data recorded by the Glacier Monitoring in Switzerland (GLAMOS) network.

The retreat of the glacier tongues and their disintegration continue unabated as a result of climate change. The previous years of 2022 and 2023 saw a total of 10% of Swiss glacier volume disappearing, more than had ever been recorded before. The loss of around 2.5% recorded this year is also higher than the mean value of the last decade. Major winter snow volumes managed to slow the loss of ice, but could not stop it. For example, 6 metres of snow could still be measured in mid-May on the Claridenfirn in the Glarus Alps, but this had disappeared completely in September. On the other hand, glaciers at levels below 3,000 metres above the sea melted completely, exhibiting losses of up to 2 metres of their average ice thickness (e.g. the Giétro Glacier in Valais, the Plaine Morte Glacier in the canton of Bern and the Silvretta Glacier in Graubünden). The loss experienced in glaciers with a southern influence was somewhat less, thanks to an abundance of snow in winter (e.g. the Basòdino Glacier in the canton of Ticino).

Almost unprecedented snow depth at high altitudes

The winter of 2023/2024 was distinguished by a contrast between mountains and valleys on both sides of the Alps. Below 1,400 metres above the sea, snow depths were clearly below average and, conversely, strikingly above average at altitudes over 2,200 metres above the sea. Heavy precipitation levels and relatively high temperatures throughout the entire six months of winter were responsible for this. Mean snow depths between November and May were among the highest since measurements began (e.g. ranking 6th in the almost 90 years of measurements on the Weissfluhjoch in Graubünden).

The volumes of snow created disappeared quickly, on account of very high temperatures recorded in July and August. August on the Jungfraujoch was even warmer than in the sweltering summers of 2003 and 2022. The depositing of dust from the Sahara during the six months of winter also accelerated snow melt, as the snow absorbed more solar energy as a result of this layer. In addition, very little fresh snow fell between mid-June and mid-September, even at 3,000 metres above the sea. This is exceptional in a long-term comparison, but has occurred ever more frequently in recent years.

Detailed report on the GLAMOS measurements

  • Comparison of ice lost in 2022, 2023 and 2024 on the Concordia Place (Konkordiaplatz) and Great Aletsch Glacier in Valais, and with the mean value of measurements between 1953 and 1983.
  • Glaciologists looking for a path through the labyrinth of crevasses on the Great Aletsch Glacier in Valais.
  • Glaciologists drilling with a measuring rod on the Gries Glacier in Valais. A network of gauges (on the right of the photo) facilitates the determination of losses over the entire surface of the glacier.
  • The collapse of the Gries Glacier in Valais becomes more obvious every year. Rocks are repeatedly encountered in glacier crevasses, indicating a considerably reduced ice thickness.
  • A measurement team climbs on the Findel Glacier (Valais) tongue covered with fresh snow to the glacier forefield with lakes, an area that was still covered by thick ice masses a decade ago.
  • Meltwater reaches the bed of the glacier from the surface through glacier mills (moulins), as seen here on the Findel Glacier in Valais.
  • The rapid glacier retreat creates spillways under the ice, as evident here on the Rhône Glacier in Valais.
  • Having come into contact with the new proglacial lake, the Rhône Glacier in Valais is retreating rapidly. A round sink hole that formed in 2023 and is now part of the lake is clearly visible.
  • The disappearance of the iconic ice ridge to the Piz Murtèl, as viewed from the Piz Corvatsch mountain station in the Grisons, clearly illustrates how the high mountain vista has been transformed.
  • The tongue of the Morteratsch Glacier retreated extensively in 2024. A gentle end to the glacier has been transformed into a 20-metre-high ice wall with a menacing glacier snout.
  • Comparison of ice lost in 2022, 2023 and 2024 on the Concordia Place (Konkordiaplatz) and Great Aletsch Glacier in Valais, and with the mean value of measurements between 1953 and 1983.Image: Matthias Huss1/10
  • Glaciologists looking for a path through the labyrinth of crevasses on the Great Aletsch Glacier in Valais.Image: Matthias Huss2/10
  • Glaciologists drilling with a measuring rod on the Gries Glacier in Valais. A network of gauges (on the right of the photo) facilitates the determination of losses over the entire surface of the glacier.Image: Matthias Huss3/10
  • The collapse of the Gries Glacier in Valais becomes more obvious every year. Rocks are repeatedly encountered in glacier crevasses, indicating a considerably reduced ice thickness.Image: Matthias Huss4/10
  • A measurement team climbs on the Findel Glacier (Valais) tongue covered with fresh snow to the glacier forefield with lakes, an area that was still covered by thick ice masses a decade ago.Image: Matthias Huss5/10
  • Meltwater reaches the bed of the glacier from the surface through glacier mills (moulins), as seen here on the Findel Glacier in Valais.Image: Matthias Huss6/10
  • The rapid glacier retreat creates spillways under the ice, as evident here on the Rhône Glacier in Valais.Image: Matthias Huss7/10
  • Having come into contact with the new proglacial lake, the Rhône Glacier in Valais is retreating rapidly. A round sink hole that formed in 2023 and is now part of the lake is clearly visible.Image: Matthias Huss8/10
  • The disappearance of the iconic ice ridge to the Piz Murtèl, as viewed from the Piz Corvatsch mountain station in the Grisons, clearly illustrates how the high mountain vista has been transformed.Image: Matthias Huss9/10
  • The tongue of the Morteratsch Glacier retreated extensively in 2024. A gentle end to the glacier has been transformed into a 20-metre-high ice wall with a menacing glacier snout.Image: Matthias Huss10/10

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