19,000 feet beneath ocean surface: Deepest undersea mine could deliver rare earths to US

A report has revealed that the United States and Japan are exploring a major deep-sea mining project near Japan’s remote Minamitorishima Island, where rare-earth-rich deposits lie roughly 19,000 feet (6,000 metres) beneath the ocean surface. The project could become one of the deepest mining operations ever attempted and could mark a significant step in efforts by the U.S. and Japan to reduce their dependence on China for strategically important minerals. The project is about far more than mining. At its core is a struggle over who controls the supply chains that underpin electric vehicles, electronics, renewable-energy technologies, advanced manufacturing and defense systems.Rare-earth elements are a group of minerals with unusual magnetic, electrical and chemical properties. They are essential to the manufacture of high-performance magnets, motors, electronics and several advanced defence technologies. Rare-earth supply chain China has built a commanding position across the rare-earth supply chain, particularly in processing and refining. That dominance has made diversification a strategic priority for the United States, Japan and other industrial economies.For Japan, the issue is especially sensitive. Tokyo has already experienced the risks associated with dependence on Chinese rare-earth supplies. The country has consequently spent years looking for alternative sources and technologies. Minamitorishima, a deposit thousands of metres below the Pacific, offers a potentially significant opportunity.Minamitorishima is a small, remote Japanese island located far out in the Pacific. Surveys have identified mineral-rich mud in the surrounding seabed, containing elements including yttrium, gadolinium and dysprosium. The mineral-bearing material is located at depths of approximately 6 kilometres. Recovering material from such depths presents enormous engineering challenges involving extreme pressure, long-distance pumping, specialized vessels and subsea equipment.Japan has already been working on the technology needed to overcome those obstacles. A Japanese government-backed programme has been developing a system designed to continuously lift rare-earth-rich mud from the seabed. Earlier plans envisaged testing the system at depths of around 6,000 metres and assessing whether it could eventually recover hundreds of tonnes of mud per day. Refining trial has been planned The immediate objective is not to suddenly create a giant commercial mine. Instead, Japan is attempting to prove that the technology works. A month-long extraction and refining trial has been planned as part of the country’s broader programme. The proposed system would lift seabed mud to the surface and then move the material for processing and separation in Japan. Japan has reportedly invested tens of billions of yen in the programme since 2018, illustrating how seriously Tokyo views the project. The next major question is whether the technology can move from an experimental demonstration to an economically viable mining operation.For the United States, the attraction is obvious: another potential source of critical minerals outside China’s dominant supply chain.The project is therefore emerging at the intersection of mining, technology and geopolitics. The U.S. wants to strengthen access to critical minerals, while Tokyo wants to build greater resilience into its own industrial supply chains.A successful US-Japan partnership could potentially go beyond simply extracting material from the seabed. It could contribute to the development of a broader mine-to-magnet supply chain, covering extraction, processing, refining and eventually the manufacture of high-value components. Analysts cited in reports on the project have described such integration as a potential way of reducing China’s influence over the sector. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Prabhat, an alumnus of the Indian Institute of Mass Communication, is a tech and defense journalist. While he enjoys writing on modern weapons and emerging tech, he has also reported on global politics and business. He has been previously associated with well-known media houses, including the International Business Times (Singapore Edition) and ANI.