Mining the deep blue sea

In today’s progressively developing world, consumption of energy and materials is at an all-time high, prompting an increase in demand for minerals, metals and fossil fuels. The high cost and infrastructure associated with mining these vast deposits often hamper efforts to obtain these valuable resources. According to the Society of Mining, Metallurgy & Exploration, almost 3/4 of the global mineral resources are in, or under, the sea and are virtually undeveloped.

At the School of Ocean and Earth Science and Technology (SOEST), faculty members Drs. Gary McMurtry and John Wiltshire have been studying marine minerals in different capacities over the course of 30 plus years. McMurtry is an associate professor in the Department of Oceanography and Wiltshire is associate chairman of the Department of Ocean and Resources Engineering in the Department of Ocean and Resources Engineering (ORE). SOEST is a leading institution of multidisciplinary research and education on the ocean, earth and atmosphere. Within SOEST, ORE’s mission is to educate top quality ocean and resource engineers to meet the needs of Hawai‘i, the nation and the engineering profession, as well as conduct and disseminate research in the field of Ocean and Resources Engineering.

While Wiltshire’s expertise lies in marine mineral deposits, marine mining and processing, submersible technology and one of McMurtry’s areas of expertise is in marine mineral formation and resources, they have jointly taught classes on marine mineral resources engineering and mineral and energy resources of the sea.  The marine mineral resources engineering course familiarizes students with the mineral resources of the ocean and the engineering challenges faced to exploit them.  The course in mineral and energy resources of the sea exposes students to the various types of marine minerals, mode of formation and its geological and economic importance.

Three major marine mineral deposits from L-R: sulfide, nodule, manganese crust.

There are three major marine mineral deposits: sulfides, nodules and crusts.  Sulfides, usually found in shallow water anywhere from 800-2,500 meters deep, are rich in gold, silver, lead and zinc.  Nodules are rich in copper, nickel, cobalt and manganese and are found in deep waters.  Crusts are rich in platinum, cobalt, nickel and manganese.

Another type of deep-sea element being studied at UH Mānoa is rare earth elements, which ironically, are not all that rare and are considered to be relatively abundant. The recent discovery of huge deposits of rare earth elements found in the deep sea near Hawai‘i presents an array of possibilities.  That is, if countries are willing to shell out millions or billions of dollars to mine them.  Rare earth elements are most commonly found in hybrid cars, photovoltaic panels, cell phone batteries and used in semiconductor industries.

McMurtry, who has studied rare earth elements since the 1980’s, notes that deep below 5,000 meters of water, the deposits are loaded with rare earth metals, which are sometimes also rich in phosphorites. Phosphate rock is most often utilized in the agricultural industry.  Almost all fertilizers contain marine phosphate, which when added to soil, provides crucial nutrients essential for plant growth. 

China is currently the leader in producing the world’s supply of rare earth elements from its mineral deposits. In fact, according to the Society for Mining, Metallurgy & Exploration, in July 2011, China surpassed current U.S. capabilities to explore mineral resources on the ocean floor by sending a submersible to over 5,000 meters, which equates to over 70 percent of the ocean floor. China’s funding and existing infrastructure enable them to dominate the world market.

Much of SOEST’s research into ocean mineralization takes place through the Hawai‘i Undersea Research Laboratory (HURL) of which Wiltshire is the director.  HURL is one of six national laboratories comprising the National Oceanic and Atmospheric Administration’s National Undersea Research Program.  Its mission is to study deep water marine processes in the Pacific Ocean.

HURL operates two deep diving (2,000 m) submersibles, the PISCES IV and PISCES V, and a remotely operated vehicle (ROV). The ROV and submersibles operate off the 225-foot research vessel, Kaimikai-O-Kanaloa, obtained for the university and largely supported by HURL. The submersibles, ROV and their mothership conduct a wide range of engineering and science research activities focusing on deep-sea geology and ecosystems and their contribution to global climatic and ecosystem changes. In addition, many students in the ORE program find thesis projects, financial support and advisors studying various aspects of the dynamics of submersible and ROV operations as well as new instrumentation, control and equipment applications. Future HURL research projects include the geology and biology of emerging and subsiding islands, marine product and fishery assessments, and processes of submarine mineral accumulations on seamounts, volcanoes, and islands.

The Department of ORE also maintains research facilities at Kewalo Basin and Snug Harbor for field work and in-ocean experiments. The field research facilities support study of ocean and coastal structures and materials, wave dynamics and sediment transport.

UH Mānoa continues to be a leading force– conducting and sharing research in the field of Ocean and Resources Engineering, as well as serving as the “go-to” source for national and international colleagues through opportunities such as seminars, conferences, consulting, work with government agencies and professional societies.

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Top photo: HURL Pisces submersible

Marine Mineral Deposits Worldwide. Source: Underwater Mining Institute.