De nouvelles perspectives pour les applications des méthodes électromagnétiques basse fréquence en archéologie

International audience ; The low-frequency electromagnetic method (or EMI for ElectroMagnetic Induction), at the crossroads of the magnetic, electrical and GPR methods, offers many possibilities of development but is also limited by important technical constraints. In spite of instrumental developments initiated during the sixties, their use has long been limited in archaeology to the mapping of apparent electrical conductivity and/or magnetic susceptibility over restricted areas or with wide mesh sampling strategies. Since the end of the 2000s, due to their application in soil science, EMI methods have been widely diffused. Multi-coils and multi-frequency systems have replaced single-frequency and single-receiver devices, then opening up new perspectives in terms of 3D spatial characterization of buried features but also in terms of soil properties analysis. The development of towed systems allowed application to landscape archaeology. This technical advance, which has been expressed in terms of amount of measurement, has prevailed over in-depth theoretical work nowadays illustrated by data inversion and analyses of sensitivity to the different geophysical properties. These two specific points, however, open up the soundness perspectives to future applications. We will discuss the instrumental limitations to which these applications face and which are often neglected by practitioners. We will also present the results of 1D and 3D modelling. ; La méthode électromagnétique basse fréquence (ou EMI pour ElectroMagnetic Induction), située à la croisée des méthodes magnétique, électrique et radar, offre de nombreuses possibilités de développement mais subit également d’importantes contraintes techniques. Malgré des développements instrumentaux initiés dans les années 60, son utilisation a longtemps été limitée en archéologie à la cartographie de la conductivité électrique apparente et/ou de la susceptibilité magnétique soit sur des surfaces restreintes soit avec des stratégies à large maille. Depuis la fin des années ...