The core of the MACIV project is an innovative multiscale temporary seismic experiment that will fill a data gap on the seismic structure of the FMC (Figure ; WP1 : Seismic data collection and distribution). The array of several hundreds of modern seismic instruments is designed to probe different characteristic scales and depths of the FMC volcanic systems with optimal spatial resolutions. The large-scale arrays will cover the entire FMC and provide first-order information on the sites and causes of mantle melting at depth and the expression of volcanism at the surface, such as the lithospheric structures of the FMC, the crustal thickness, the impacts of the Variscan inheritance, or the Cenozoic rift system. On a smaller scale, the combination of intermediate-band and 600+ short-period sensors in dense arrays configurations will provide images of the upper crust below the volcanoes and illuminate their plumbing systems. The enhanced earthquake detection power of the arrays will document active faults and possible plumbing systems of the youngest volcanoes.

All seismic data will be collected, validated, archived and distributed by the national data center RESIF-DC hosted by University Grenoble Alpes (WP1). They will be available to all project participants in near-real time. Leading-edge seismic data analysis will be carried out by a team of seismologists with strong skills in seismic imaging and seismic detection methods (WP2 : Seismic tomography using leading-edge methods, WP3 : Seismicity detection and localization). Their results will be jointly interpreted (WP4 : Joint interpretation of seismic and geological data) with geologists specialists of the FMC (WP4.1 : lithospheric structures and Variscan inheritance) and with petrologists and geochemists specialists of FMC volcanoes (WP4.2 : Contribution to the understanding of volcanism in the FMC : from the causes of mantle melting at depth to shallow magma plumbing systems). At the smallest scale, the Escarot mofette will be monitored by geophysical and geochemical means in WP5 (not funded by ANR). The project is therefore fully interdisciplinary.

Updated on 11 janvier 2024