Ruptures and tremors : Seismic and gravity hazards in the Chamonix valley

Project description

The Chamonix valley is subject to both seismic and gravity hazards. More specifically, in the Aiguilles Rouges massif, these two aspects are closely linked. The Remuaz tectonic fault, capable of producing Mw ≥ 6 earthquakes over the past millennia, cuts across a wide zone of gravity rupturesaffecting the slope over several km. The strongest known historical earthquake in the area (Mw 5.3 in 1905) triggered numerous collapses, including one that significantly affected the famous Aiguillette d’Argentière at the northern end of the Aiguilles Rouges. We can therefore assume that stronger earthquakes could reactivate major gravity structures.
A combined geological and sub-surface geophysical approach will enable us to image the bedrock structure at depth and estimate the volume of rock uncoupled from the slope. At the same time, we will install a high-resolution distancemeter at the main fracture to continuously measure and monitor displacement along it. This study will complement the ongoing long-term analysis aimed at determining the chronology of past seismic and gravity events.