Key points
- NORI Environmental Manager Dr Michael Clarke presents preliminary benthic plume data from NORI-D, drawing on 11 years and 20 offshore campaigns plus 2022 test mining that collected over 4,500 tons of nodules.
- Field and lab data show roughly 95 percent of the sediment plume forms a low-lying gravity-driven current that stays within a few meters of the seafloor rather than lofting into upper water layers.
- Sedimentation is largely confined within the 4km by 2km test field, dropping to 0.5-0.1 millimeters at 500 to 1,000 meters away, a boundary confirmed independently by thorium-234 tracing.
- NORI has committed to delay its ISA exploitation application until after the July 2025 meetings to allow more environmental data collection and give the ISA time to finish mining regulations.
