Key points
- TMC found that sediment plumes form turbidity currents that follow the seabed’s contours and flow downslope into depressions, letting engineers predict where sediment will settle with high accuracy.
- The original straight-line mine plan required 80 to 100 km runs with the support vessel tracking the collector via dynamic positioning, which consumes significant fuel.
- Sharper collector turns demonstrated during the 2022 test mining campaign enabled a shift to sweep mining, where the vessel stays stationary while the collector sweeps back and forth over 500 to 1,000 meters.
- Currents at 4,000 meters behave more like tidal sloshing than the directional currents found in shallower water, and tracking seasonal current shifts lets planners mine upstream so the plume settles into already-mined areas.
