Deep Sea Minerals - Vol 2 - Manganese Nodules

Exploration 4.1 Exploration involves the identification, delineation, and evalua- tion of deep sea mineral resources and generally requires sophis- ticated, multipurpose research vessels using advanced technol- ogies such as deep sea mapping equipment, remotely operated vehicles, photographic and video systems, and sampling devices. Manganese nodule exploration typically involves: • Mapping the bathymetry and sea-floor topography to deter­ mine areas that are suitable for nodule occurrence and future mining operations; • Determining nodule coverage using high-resolution imagery; • Nodule sampling to determine grade and confirm nodule abundance;

• Bulk nodule sampling to obtain sufficient quantities for min- eral processing studies; • Geotechnical studies to feed into engineering design for mining technology; • Calculating the size and grade of the resource; and • Carrying out environmental baseline studies and impact assessments. Manganese nodules occur over areas of thousands of square kilometres. To date, the most effective method of exploration has involved a staged exploration strategy, start- ing with large broad-scale acoustic surveys and followed by finer-scale sampling.

GPS

Multi beam eco sounder

Free fall grab

Narrow beam sounder

Bentic multi-coring system

Large gravity corer

Finder-installed deep sea camera

Multiple corer

Dredge bucket

Finder-mounted power grab

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

Figure 22. Acoustic Survey.

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