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  • Discovery of Deep Sea Rare Elements in the Atlantic Ocean

    19.05.2017 | Comments | Environment | 106 Saule Akhmetkaliyeva

    Researchers from the UK’s National Oceanography Centre have discovered rare minerals in the Atlantic Ocean about 500 kilometers away from the Canary Islands at Tropic Seamount. Tropic Seamount is a 3,000 meter tall mountain which is located 1,000 meters below the surface of the water. The main element discovered in the samples collected at the site is tellurium. The concentration of this element in the seamount samples is 50 thousand times higher than in the deposits discovered on land. Tellurium is an element used for advanced types of solar panels (Shukman, 2017). Tellurium is a semiconductor and has a greater conductivity when exposed to light, making it very useful for photovoltaics. Cadmium telluride (CdTe) photovoltaics is the second most commonly used photovoltaic technology after the conventional use of crystalline silicon solar cells. CdTe solar cells are relatively quick and cheap to manufacture. A thin film of CdTe is capable of absorbing and converting sunlight into electricity. However, while Cadmium is abundant, the abundance of tellurium is comparable to the abundance of platinum in the world (Energy.gov, n.d.).

    According to the studies, the amount of tellurium reserves at the site is about 2,670 tons, which is one-twelfth of the global total amount of discovered deposits of the element. Moreover, it has been estimated that the use of this amount of deposit in solar panels would meet 65% of energy demand in the United Kingdom. Traces of some other rare minerals and elements were also discovered in the samples. These minerals can also be used for renewable energy development as they can be used in manufacturing of wind turbines (Shukman, 2017).

    Marine mining is of a great economic interest due to the abundance of marine sources compared to the land deposits. Moreover, demand for some Rare Earth Elements is growing as new technologies are emerging. In this light, while shallow water mining for minerals such as gold has been around for a long time, deep sea mining is yet to take a commercial turn. So far, there were three main deposits that have caused industrial interest: polymetallic nodules (manganese nodules) – rich in manganese, nickel, cobalt, copper, lithium, molybdenum, iron and Rare Earth Elements, seafloor massive sulphide – rich in high-grade copper, gold, silver, zinc and other trace metals, and cobalt-rich ferromanganese crusts – rich in cobalt, nickel, copper, iron, manganese, rare metals such as tungsten, platinum, bismuth, tellurium and Rare Earth Elements. Additionally, marine phosphate used as fertilizers and methane hydrates used for conventional energy production are often discussed alongside with deep sea mining for rare minerals and elements. In this light, in order to prevent a gold rush in the ocean, the International Seabed Authority (ISA) was established in Jamaica in 1994. The ISA gives license areas in international waters to interested states while ensuring that developing countries would also benefit from deep-sea mining activities (World Ocean Review, 2014).

    Even though tellurium is to be used for renewable energy generation, the issue of deep sea mining is highly controversial as it can cause irreversible damage to the marine ecosystem. Some proponents of deep sea mining argue that mining from the seabed would create a smaller digging area than mining on land. However, deep sea ecosystem is poorly understood making it highly prone to risks and impacts of deep sea mining. Activities such as extraction, disposal of debris, shipping, separated seawater and tailings cause threat to the marine health, while extreme pressure and cold temperature make the extraction of deep sea minerals even more complicated.

    Currently, due to the lack of previous in-depth studies of the impacts of deep sea mining, the long-term impacts of such operation are unknown (World Bank, n.d.). In this light, currently, the risks of mining on seabed are being evaluated. However, to date, deep sea mining has not taken place, so it is hard to fully predict the risks associated with such operations. Exploration of minerals is expected to have minimal impacts, while test mining, drilling, dredging and exploitation can cause some severe damage to the marine environment, some of it might even be permanent. Deep sea mining would also have some negative economic impacts on the fisheries industry as the fish habitats are to be destroyed as a result of mining operations. It is worth mentioning that one of the risks that have not yet been studied is seismic activity that can be triggered by mining operations (World Bank, n.d.).

    Even though marine extraction of minerals would not have direct effect on humans, it would damage the entire marine system. The main concern is caused by the amount of plumes of dust as a result of digging of minerals. The water would transfer the dust to long distances. According to the results of the experiment conducted in the framework of the Tropic Seamount expedition, dust plumes are hardly detectable away from the radius of 1 kilometer. Also some studies suggest that most of the marine creatures would be able recover in the period of a year. However, it would take several decades for some of them to fully recover. A study of tiny organisms conducted on the floor of the Pacific Ocean at the Clarion-Clipperton Zone where polymetallic nodules are present found that there is an abundance of single-celled organisms, known as xenophyophores. The main role that the xenophyophores play in the marine ecosystem is the formation of shells that serve as habitats for many other creatures (Shukman, 2017). Therefore, before taking any steps towards the mining of the seamount it is important to conduct further studies evaluating the risks of dee-sea mining at the site along with taking precautionary measures in order to avoid accidents.


    References:

    Energy.gov (n.d.). Cadmium Telluride. Office of Energy Efficiency & Renewable Energy.

    Retrieved from https://www.energy.gov/eere/sunshot/cadmium-telluride.

    Shukman, D. (2017). Renewables' deep-sea mining conundrum. BBC. Retrieved from http://www.bbc.com/news/science-environment-39347620.

    World Bank (n.d.). Precautionary management of deep sea mining potential in Pacific Island countries: Draft for discussion. The World Bank.

    World Ocean Review (2014). 3 Marine resources – opportunities and risks. maribus gGmbH, Pickhuben 2, D-20457 Hamburg, Germany. ISBN 978-3-86648-221-0.


    Note: The views expressed in this blog are the author's own and do not necessarily reflect the Institute's editorial policy.

    Tags: Atlantic Ocean, Rare Elements, Environment

Author

  • Junior Research Fellow

    Saule Akhmetkaliyeva

    Saule Akhmetkaliyeva is a research fellow in the Eurasian Research Institute at H.A.Yassawi Kazakh Turkish International University. She holds a BS in petroleum engineering from the Kazakh National Technical University named after K.I.