MACIV (2023 -2028)

The volcanism of the Massif Central (MCF) is considered potentially active since the last eruptions date back 6700 years ago. The Eifel region (Germany) shows signs of current magmatic activity, although its volcanoes belong to the same European Cenozoic rift system as the MCF. However, geophysical knowledge on the sources of volcanism in the Massif Central is limited to the mantle mini-panache model resulting from the last seismic imaging experiment 30 years ago. To better understand the volcanic hazard and contribute to a better assessment of mineral and geothermal resources associated with volcanism, the MACIV project will implement the most innovative seismic tomography methods in the Massif Central. This essentially experimental project is proposed by a multidisciplinary team of geophysicists, geologists and volcanologists from ISTerre, IRAP and GET (Toulouse), LMV (Clermont-Ferrand) and ITES (Strasbourg). Funded by the ANR for 5 years [2023-2028], the project leaders are Anne Paul and Aurélien Mordret (ISTerre, team Ondes et Structures).

From 2023 to 2027, five temporary multi-scale seismological networks will be deployed throughout the Massif Central. We will install a total of 750 seismological stations, including 35 broadband stations (LB) in a sheet covering the entire massif for 3 years, 65 medium-band stations (MB) on three profiles across the main volcanic complexes for 2 years, and 650 short-period sensors (SP) of the "nodes" type for one month (see map). The temporary large-scale networks will complete the permanent French network (FR & RD) and will allow to specify the position and the geometry of the volcano-magmatic sources in the mantle, the melting conditions, their links with the Variscan and Cenozoic structures. At the kilometer scale, arrays of several hundred SP sensors will be deployed in the fall of 2025 on volcanoes to study magma transport systems in the crust and the links between volcanic systems, mineral deposits and geothermal resources. These multiscale sensor arrays will significantly improve the seismic event detection capabilities of the permanent network, and will enable the development of a long-term volcanic activity monitoring strategy.

The MACIV project will thus provide a unique seismological database that will be exploited for years to come to better understand intraplate volcanism. The broad-band station array is also the French contribution to the large European project "AdriaArray", in which temporary seismological stations are being installed from the Massif Central to the Carpathians (see map). The seismological data of this part of the network are freely available from the RESIF-SI data center. 

Currently, teams from ISTerre and IRAP are crisscrossing the Massif Central to prospect the sites that will host the project's LB stations. A first LB station was installed at the end of February and several others will be installed in April. The data, collected in real time, are disseminated by the RESIF-SI data center and are already accessible to all.

The data from the broadband stations are accessible on RESIF data portal (https://seismology.resif.fr/networks/#/XP). 

The station names are formated as NET.STA = XP.FRXXA.