How mantle plumes interact with subducting slabs from the mid-mantle to the Earth’s surface.

Mapping flow in the Earth’s mantle is key to advance our fundamental understanding of deep Earth processes, which control plate tectonics, volcanism, earthquakes and mountain building. By building the clearest picture so far of how mantle plumes can interact with subducting slabs from the mid-mantle to the Earth’s surface, this study self-consistently explains many unique tectonic and geological features in the Tonga-Kermadec subduction region and opens the way to understand mantle flow in other regional settings.

This study suggests that significant interactions between subducting plates and mantle upwellings may be more common on Earth and more important than previously thought. Up to now, such interactions may have remained largely undetected due to limited seismic resolution and to the lack of fully concerted seismic and geodynamical interpretations. The new models open the way to hunt for possible hidden plumes beneath other slabs stagnating in the mid-mantle, to predict their geochemical and subduction kinematics signature in the geological record and to unravel their role on slab deformation, with potential strong implications in terms of the nature of material exchange between the Earth’s upper and lower mantle.

Full article: Upper- and mid-mantle interaction between the Samoan plume and the Tonga–Kermadec slabs. Sung-Joon Chang, Ana M.G. Ferreira & Manuele Faccenda. Nature Nature Communications 7, Article number: 10799 doi:10.1038/ncomms10799.