Scientific discovery
The melting of glaciers increases the seismic risk in the mountains
A Franco-Swiss study reveals that the seismic hazard under Mont-Blanc has been ten times higher since 2015 than before. A crucial discovery.
The seismic activity under the Mont-Blanc massif has increased considerably since 2015 due to the melting of glaciers.
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- The seismic activity of Mont-Blanc has intensified since 2015
- Experts note a seismic risk multiplied by ten in this region.
- The melting of the glaciers modifies the hydraulic pressure in the deep rocks.
- This discovery potentially concerns other mountainous regions in the world.
The first scientific proof of a link between climate change and seismic risk in the mountains has just been established. Seismic activity under the Mont-Blanc massif has increased considerably since 2015 due to climate change, according to a Franco-Swiss study recently published and relayed by the RTS and the ATS. According to researchers, the seismic hazard is now ten times higher than before 2015 in this Alpine region.
A persistent seismic activity
According to the Swiss Seismological Service (SED), the chain of major johes, which is part of the Mont-Blanc massif, has experienced a persistent sequence since fall 2015, while only isolated earthquakes had been recorded before. This new activity follows a marked seasonal scheme, with a particularly high frequency in autumn.
The Mont-Blanc massif has experienced a persistent sequence since fall 2015.
Earth and Planetary Science Letters
The study, conducted by SED scientists at theEPF de Zurichfrom the office of geological and mining research in Montpellier and the Institute of Earth Sciences in Grenoble, reveals that, during the period from fall to spring, the risk that an earthquake of magnitude 3 or more occurs within twenty-four hours can be temporarily multiplied by a factor of 10,000.
Climate change is directly implicated in this phenomenon. The heat waves melt the permafrost and accelerate the ice mel in these regions. This cast iron causes an increase in landslides, modifying the infiltration pathways of cast iron water.
These changes influence the pressure of interstitial water even in the deep rock formations and alter the tension relationships in the basement, explaining the increased seismic activity in areas hitherto spared by earthquakes.
An unprecedented study on seismic activity
If seasonal variations in seismic activity linked to interstitial pressure changes have already been observed elsewhere, this is the first time that a study has proven that this phenomenon, accentuated by climate change, can lead to a significant increase in local seismic hazard.
This discovery, published in the journal “Earth and Planetary Science Letters”, is crucial to improve the prevention of earthquakes in Alpine regions. According to the SED, the phenomenon is not limited to the Mont-Blanc massif, but potentially concerns other high mountain or Arctic regions around the world.
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