Key points
- A peer-reviewed study published in Nature used thorium-tracing techniques to track how far seafloor sediment plume particles travel from a mined area.
- The study found plume concentrations return to background levels, comparable to a single grain of sand in a liter of water, within 1-2 km of the mined area.
- Researchers measured thorium radioactivity in sediment cores taken with a multi-corer at varying distances from the directly mined area to track particle spread.
- The findings counter prior claims that seafloor sediment plumes travel thousands of kilometers, which the study says were never grounded in scientific data.
