Overview

• Researchers led by Verena Simon at ETH Zürich have documented a strong annual pattern of earthquakes beneath the Grandes Jorasses that began in autumn 2015.
• Analysis reveals that surface meltwater infiltrates a major fault zone exposed by the Mont-Blanc Tunnel, altering pore pressures and triggering seismic events.
• Intensified heatwaves since 2015 have accelerated glacier and permafrost melt, creating new pathways for subsurface water to destabilize rock formations.
• The study published in Earth and Planetary Science Letters finds that quake hazard beneath the Mont-Blanc Massif can surge up to 100 times during peak meltwater flow.
• The research team urges an urgent reassessment of Alpine seismic hazard models and preparedness measures for mountain communities.