Scientists have measured the sediment bloom left in the wake of a deep sea mining vehicle as it went about its operations.
The team of MIT ocean scientists conducted their 2021 study in the Clarion Clipperton Zone (CCZ) in the Pacific Ocean. The team equipped a prototype to take samples and monitor the plumes caused by a mining vehicle as it traversed the sea floor at 4,500m/ 14,765ft.
The scientists discovered the vehicle’s plume did not rise as previously predicted. Instead, it stayed within 2m/7ft of the sea floor and created a “turbidity current” before falling back to the bottom of the ocean.
According to Thomas Peacock, professor of mechanical engineering at MIT and study co-author:
“It’s quite a different picture of what these plumes look like, compared to some of the conjecture…Modeling efforts of deep-sea mining plumes will have to account for these processes that we identified, in order to assess their extent.”
Describing the current dynamics, Peacock added:
“The turbidity current spreads under its own weight for some time, tens of minutes, but as it does so, it’s depositing sediment on the seabed and eventually running out of steam…After that, the ocean currents get stronger than the natural spreading, and the sediment transitions to being carried by the ocean currents…Our study clarifies the reality of what the initial sediment disturbance looks like when you have a certain type of nodule mining operation…The big takeaway is that there are complex processes like turbidity currents that take place when you do this kind of collection. So, any effort to model a deep-sea-mining operation’s impact will have to capture these processes.”
You can find the original study here.