Subduction zones are repeatedly devastated by large earthquakes, tsunamis or volcanic eruptions and host the greatest vertical movements on Earth. Stresses and energy release via earthquakes together with fluid-mediated mass transfer are highly focused on the plate interface, where they interact on a wide range of spatial and temporal scales, both at short- (1e-4 yr) and longer time-scales (1e6-1e7 yr).

Recent observations suggest that the architecture of the plate boundary is complex and may consists of a several kilometers thick subduction interface. However, despite a wealth of recent geophysical and petrological data, the nature, structure and properties of this plate interface are still largely unknown, and the following fundamental questions remain unanswered, calling for thorough reexamination: What are the dimensions and the geometry of the plate interface? What are the respective amounts of crustal/mantle/sediment present along the interface? Can we adequately model time-integrated material fluxes (both rocks and fluids) along this interface, and how does this impact the global recycling of elements? How do these rocks deform and get imbricated, and can we link this to seismicity and megathrust earthquakes? What are the nature and physical properties of the plate boundary that control the seismogenic zone and its updip and downdip limits? What are the factors controlling the earthquake nucleation and rupture propagation and how do they interplay?

Time has come to fully combine the extremely dense datasets and high-end new analytical tools that are now available in order to get a refined view of the physical conditions and processes at work along the subduction interface. We welcome contributions from all disciplines, with a special focus on high-resolution lithospheric and crustal-scale constraints from geophysics and geochemistry, high-precision thermobarometry and P-T-t paths, fully coupled thermodynamic and mechanical numerical modelling. This session also aims at fostering joint collaboration and research and at bridging the gap between the various communities.