A new study suggests that climate change could be triggering minor earthquakes in the Alps, raising broader concerns about global warming's impact on seismic activity. Researchers from ETH Zürich have found that intense glacier melt, driven by rising temperatures, can infiltrate underground fault lines and increase the risk of tremors.
The study, published in Earth and Planetary Science Letters, focuses on seismic activity beneath Grandes Jorasses, a glacier-covered peak in the Mont Blanc massif. Seismic records showed a sharp increase in small earthquakes following a 2015 heatwave. Researchers detected over 12,000 previously overlooked micro-earthquakes since 2006. These tremors coincided with glacier meltwater percolating into deep rock layers, a process that weakens geological faults.
Lead author Verena Simon and her team observed that the strongest heatwaves led to more frequent and stronger earthquakes, though often with a one- to two-year delay. This indicates that meltwater gradually builds pressure along fault lines until a "triggering point" is reached.
Scientists have long known that pressurised water can trigger seismic activity. Similar mechanisms are seen in fracking and geothermal energy operations. The new study adds weight to the theory that climate change is influencing natural seismicity, not just in the Alps but potentially in other glaciated regions such as the Himalayas.
While the tremors themselves are currently too weak to pose major threats to infrastructure like the Mont Blanc tunnel, the findings are a warning sign. If replicated in other mountain ranges, melting glaciers may contribute to larger, more dangerous earthquakes in the future.
