Some valuable metallic commodities may be found in higher concentrations in some areas of the deep sea than on land.
Hydrothermal Vent Systems (HVS) occur on the seafloor and exhale hot, 200-400 °C, mineralising fluids. Once this fluid comes into contact with seawater and cools, it precipitates metals, making HVS literal hot spots for Seafloor Massive Sulphide (SMS) deposits rich in Cu, Zn, Pb, Au and Ag. Vent systems are often extensive, meaning the potential for reserves is fairly high. Recent estimates of global deposits of SMS amounts to 6 × 108 tonnes; 3 × 107 tonnes of this being copper and zinc. Some hydrothermal vents have the potential to also form manganese-rich polymetallic nodules which can contain higher concentrations of metal than terrestrial counterparts. So why aren’t we mining the oceans yet?
In February 2015, exploration companies, experts and researchers from around the world participated in the annual Deep Sea Mining Summit in Aberdeen, Scotland, to discuss topics ranging from new mining technologies, to the impact of excavation on the ocean’s ecosystems. Some of those who attended include leading deep sea exploration companies Neptune Minerals Inc, and Nautilus Minerals Inc who currently have tenements in countries in the Western Pacific including Papua New Guinea, and New Zealand, respectively. But securing licences hasn’t come easy, in the case of Nautilus, access to their Solwara-1 project was only granted by the PNG state last year.
We’ve known about SMS deposits, polymetallic nodules, and other forms of ocean resources since the 1960’s. However, it’s only in recent years, and after many false starts, that exploration has managed to get going; mainly due to reluctance based on the potential toxic threat to vent fauna during excavation, the lack of technological advancement, and operation costs.
Deep sea mining has a way to go before it becomes a stable commercial venture, and probably a way to go after that before we’re able to sufficiently limit the threat to ocean habitats in our zeal. However, the potential payback remains great, considering the Earth is 71% ocean, and 29% land, and look what we’ve managed to get out of the land so far…
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