On March 10, 2025, the Norwegian volcanic island of Jan Mayen in the Arctic Ocean was rocked by a magnitude 6.5 earthquake. This is the strongest seismic shock in the region in the last hundred years, and it triggered a rock avalanche that buried a large part of the Kjerulf glacier.
New studypublished in the journal Proceedings of the National Academy of Sciences, argues that the earthquake was only a trigger. The real reason for the scale of the collapse is said to be the degradation of permafrost caused by Arctic warming.
The team combined seismic data, infrasound observations, satellite imagery, satellite measurements of surface displacements and climate statistics. The combination of these sources indicated that the slope of the volcano was losing stability long before the shock.
Guilherme V. S. de Melo, lead author of the paper and postdoc at the marine geodynamics unit of the GEOMAR Helmholtz Center for Ocean Research in Kiel:
The 2025 earthquake is a prime example of cascading natural hazards. Our study is the first to document an earthquake-induced rock avalanche on Jan Mayen Island. The volcanic slope likely became increasingly unstable due to permafrost degradation.
Jan Mayen is located adjacent to the oceanic Jan Mayen Transform Fault, which displaces the Mid-Atlantic Ridge and separates the Eurasian and North American plates. Due to its proximity to the active plate boundary, earthquakes are common here.
At the same time, satellite observations over the past 40 years have not recorded a single collapse comparable in volume of debris to the March 2025 event. It was this anomaly that led researchers to look for an additional factor.
First, the connection between the shock and the avalanche was confirmed using local seismic records, data from global navigation satellite systems, and high-resolution images. The collapse occurred within three minutes after the main shock.
The volume of the fallen rock was estimated at about a million cubic meters, the debris covered from 30% to 50% of the surface of the Kjerulf glacier. Radar surveys four hours after the earthquake showed another consequence – ice calving on the shoreline of the nearby Weyprecht Glacier.
Next, the researchers looked at temperature records on the island from 1970 to 2025. Average summer temperatures have risen from 2–3 degrees Celsius in the 1970s to 5–6 degrees in recent years, while winter temperatures have risen from about -7…-6 to -2…-1 degrees.
It is separately noted that extreme cold below -20 degrees became rare already in the 1990s. This dynamic is consistent with the Arctic amplification effect, in which the Arctic is warming noticeably faster than the rest of the planet.
Permafrost works like natural cement – ice holds soil and rock together, just as a binder holds concrete. As temperatures warm, this cohesion weakens and the slope becomes vulnerable to any strong shaking.
Jan Mayen itself is practically deserted, with only the staff of the weather station on the south-eastern coast living there. However, the authors warn that similar processes are taking place in populated or actively visited areas of the Arctic.
Guilherme V. S. de Melo:
Global warming and permafrost degradation can gradually weaken slopes and glaciers, thereby increasing the likelihood of cascading hazards—as recently happened in the Nepal-China border disaster.
There, the immediate trigger was the collapse of a glacier and ice-rock mass, and in the case we studied on Jan Mayen, an earthquake. In a broader context, both events highlight how a warming climate is making glacial regions increasingly vulnerable to cascading hazards.
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The work points to a growing need to study the interactions of climate, cryosphere and seismic activity as a single system. The Jan Mayen event was a clear case of seismic and warming working together.
