Preferential Fluids Ascent Paths Revealed by Coupling Chemical, Electrical and Magnetic Methods: Insights for Risk Mitigation in a Long‐Dormant Volcanic Province (Monts Dore, France)

Abstract Risk mitigation in long‐dormant volcanic provinces is often hampered by the lack of information about potential eruptive scenarios. It is the case of the Monts Dore volcanic province (France), where the last eruptive sequence occurred about 7,000 years ago in lake Pavin. While the main recent interests focused on potential limnic eruption from the lake due to CO 2 storage in the deep‐water layer, no information is provided about the assessment of lava flow hazards. In this study, an innovative approach is led by coupling geochemical (soil CO 2 degassing) and geophysical (magnetism, electrical resistivity tomography) surveys to identify (hidden) areas and structures marked by fluid circulation and alteration processes. These preferential paths for current fluid ascent may be considered, due to their high permeability, as potential paths for magma ascent in case of volcanic unrest. In such a hypothetical scenario, a priori lava flow modeling can help in discriminating the most exposed infrastructural areas and thus provide new insights to local authorities regarding land use. Our results highlight that, even in long‐dormant volcanic provinces, common tools used on active volcanoes for risk assessment may be applied to improve relevant risk mitigation strategies.