Deep Sea Minerals - Vol 3 - Cobalt-rich Ferromanganese Crusts

Exploration 4.1 Exploration involves the identification, delineation and eval- uation of deep sea mineral resources and generally requires sophisticated, multipurpose research vessels using advanced technologies such as deep sea mapping equipment, remotely operated vehicles, photographic and video systems, and sam- pling and drilling devices (Figure 14). Exploration for ferromanganese crusts typically involves the fol- lowing steps: • bathymetric mapping of seamounts using acoustic survey- ing (for example, wide-swath Multi-Beam Echo Sounder sys- tems) and analysis of bathymetric data (Figure 15);

• determining distribution of hard-rock outcrops and sediment- covered areas of seamounts using back-scatter images from side-scan sonar systems. These images can be ground-truthed using camera/video tows. Small-scale features can be imaged using an Autonomous Underwater Vehicle (AUV) equipped with bathymetry, side-scan, and photo/video capabilities; • ferromanganese crust sampling to determine metal grade and crust thickness. Once sampling sites are identified, dredge hauls, TV grab samplers, and core samplers can ob- tain samples using winches on the ship. More detailed and precise sampling can be carried out using a remote operated vehicle (ROV).

GPS

Multi beam eco sounder

ROV (Remotedly operated vehicle)

Free fall grab

Dredge bucket

Finder-installed deep sea camera

Sources: adapted from Japan Oil, Gas and Metals National Corporation.

Figure 14. Exploration tools.

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