A comparison of opportunity and risk in deep-sea and terrestrial mining projects

摘要

The existence of metalliferous mineral deposits on the deep-sea floor has been known since manganese nodules were discovered in the Arctic Kara Sea in 1868. Modern exploration to define commercially viable base and precious metal deposits began in the 1970s and gained further momentum in the last decade. High grade deposits have been delineated but investors remain cautious, many considering deep sea mining projects to be riskier than terrestrial projects.This paper compares opportunities and risks presented by terrestrial mining projects with those presented by deep sea mineral deposits (Table 1). The Solwara 1 volcanic-hosted massive Cu-Au-Ag sulphide deposit, the Atlantis II Deeps sedimentary base metal sulphide deposit, and the Mn-Ni-Cu-Co nodule deposits of the north-eastern Pacific Ocean are used as examples. These are advanced deep-sea projects with published Mineral Resource estimates, on the cusp of development. Off-shore diamond mines in Namibia are also considered. These examples provide a basis for comparing exploration and geological uncertainty, the technical risks of proposed mining systems, and the potential environmental and social impacts. This paper argues that in many respects, the risks of exploration and development of seafloor resources are lower than for terrestrial resources and as time progresses, the balance will tip further in the favour of seafloor resources. The post-closure management of deep-sea mining projects may also be much less problematic or burdensome than for competing land-based projects.The limited precedents for seafloor mining may currently challenge main stream investors and regulators, but with several groups on the verge of committing to trial or full-scale mine development, this impediment may disappear in the near future.