Rapid glacier movement and landslides at Birch Glacier force evacuation, prompt monitoring initiative in Switzerland
As landslides and rapid glacier movement continue above the village of Blatten, Switzerland, the government has announced plans to establish a national ground monitoring system using satellite data. The aim is to anticipate ground movement-related threats, such as those currently occurring at the Birch Glacier above Blatten.
Webcam image of the deforming slope at Blatten in Switzerland on May 26, 2025. Credit: Bergfex
- Update (May 28) — The glacier collapsed during the afternoon hours of May 28, burying the village of Blatten. One person has been reported missing, and many houses were completely flattened. According to the authorities, around 3 million m3Â (106 million ft3) of rock, ice and debris fell from the mountain onto the village during the glacier collapse.Â
The Swiss government plans to use the European Space Agency’s (ESA) Sentinel-1 satellite to monitor ground movements across the country in order to anticipate landslides, rockfalls, and other ground movement-related threats.
This development follows ongoing landslides above the Valais village of Blatten, where large volumes of rock have fallen from the Klein Nesthorn onto the Birch Glacier, significantly accelerating its movement.
Evacuations in the village began on May 17 due to the risk of rockfalls and landslides. By May 19, nearly the entire population had been evacuated along with livestock as part of pre-emptive measures.
Already + 100,000 m3 fallen from the Klein Nesthorn N face at ~3200 m asl, and something between 1 to 5 Millions m3 more are 'forecasted'…
— Melaine Le Roy (@subfossilguy) May 19, 2025
That's quite a thing!
Blatten village evacuated
The 'Crumblocene' is definitely a nice time to live!https://t.co/5A2WaVIEFG pic.twitter.com/Kkt7Rj27VD
When the evacuation order was issued, the team at Hotel Fafleralp was preparing for the start of the season. These plans were halted, and the staff have remained at the hotel at the upper end of Blatten for several days.
The glacier experienced significant acceleration between May 23 and 24, with its movement speed doubling overnight to approximately 4–4.5 m (13–15 feet) per day. This increase was accompanied by tilting movements at the glacier’s front, basal sliding, and the formation of numerous cracks.
The unstable rock mass is estimated to be substantial, with initial figures ranging from 2–5 million m³ (71–177 million ft³) to between 4–6 million m³ (141–212 million ft³).
At least 17 m (56 feet) of displacement was recorded in the days leading up to May 20, and by May 24, tens of thousands of cubic meters of debris had already been deposited at the base of the slope.
Update of the situation at the Klein Nesthorn landslide (Blatten)
— Melaine Le Roy (@subfossilguy) May 22, 2025
2M m3 have broken off and 3M are unstable!
'The pressure on the glacier is increasing and there are concerns that it could collapse, as it has accelerated by 0.5 to 0.8 m/day' (Matthias Ebener)
Pomona pic.twitter.com/dOlakN5zAI
On May 27, a significant collapse occurred at the front of the Birch Glacier above Blatten, involving a large volume of ice and rock that triggered avalanches down the steep slope.
As of May 28, the glacier continues to move at a rate of up to 10 m (33 feet) per day. Josianne Jaggi from the regional command staff reported that approximately 9 million tons of debris are pressing down on the glacier, which remains the greatest risk due to the uncertainty of whether it could break off all at once.
UNBELIEVABLE !
— Melaine Le Roy (@subfossilguy) May 19, 2025
The Alps are collapsing in real time!
The whole sequence of the Lauchernalp webcam from 5:45 to 9:45 pm
This shows the summit of the Klein Nesthorn (upper tip of the triangular face in the middle) LITERALLY SLIDING to the north (left)!
Gif @AlexModesto73 pic.twitter.com/ouHfrUPEkl
Experts consider the fact that the landslide is occurring in a series of small falls rather than one major event to be a favorable scenario. However, the primary concern remains the glacier, which is accelerating downhill.
Landslides expert Dr. Dave Petley outlined three primary scenarios that could develop as the situation evolves above Blatten. One possibility involves a further major collapse from the Klein Nesthorn, which could mobilize both the debris on the glacier and the glacier itself, generating a significant flow. While this would represent the worst-case outcome, recent observations suggest that the likelihood of such a large-scale event has decreased compared to the previous week.
Another scenario centers on the collapse of the glacier itself, which could trigger a rock and ice avalanche cascading down the slope. Although this would be a major event and could pose a risk to some of the houses in Blatten, it would also have the effect of removing much of the hazard by releasing the accumulated material in a single episode.
The third, and currently most probable, scenario is a continuation of the smaller, but still significant, collapses at the front of the glacier. If this pattern persists, the village could face a prolonged period of risk, as repeated minor failures gradually bring the glacier to a new state of equilibrium. While this outcome would likely result in less immediate damage, it would also extend the period during which the residents of Blatten are unable to return home.
Dr. Petley notes that the actual progression may differ from these scenarios, but based on current conditions and his experience, the ongoing sequence of smaller collapses appears the most likely at this stage.
With ongoing landslides preventing residents from returning to Blatten, the Swiss government is moving forward with plans to establish a nationwide ground monitoring system to better anticipate such hazards in the future.
The government is planning to establish a national monitoring system based on data from the European Space Agency’s (ESA) Sentinel-1 satellite. The Federal Office for the Environment (FOEN) has commissioned a specialist company in Barcelona to obtain and process the data.
The first maps and analyses are expected by the end of 2025—more than a year behind the original schedule. The FOEN cited a change of supplier to better meet technical requirements but did not provide additional details.
Update
The glacier collapsed during the afternoon hours of May 28, burying the village of Blatten and leaving one person missing.
According to the authorities, around 3 million m3Â (106 million ft3) of rock, ice and debris fell from the mountain onto the village during the glacier collapse.
Read more:
Massive landslide from Birch Glacier collapse buries Blatten, Switzerland
May 28, 2025
A massive landslide triggered by the collapse of the Birch Glacier destroyed the village of Blatten, Switzerland, on Wednesday, May 28, 2025. One person has been reported missing, and many houses were completely flattened.
Rishav is a skilled researcher specializing in extreme and severe weather reporting. He combines exceptional research capabilities with scientific precision to deliver clear, data-driven articles. Known for uncovering critical information, Rishav ensures his work is accurate, insightful, and impactful. His passion for both science and literature fuels his dedication to producing high-quality news articles. You can reach him at rishav(at)watchers(.)news.
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