Discovery of rare-earth minerals off Japan coast secures 780 years of industrial demand: study
Mud from the seabed off the Ogasawara Islands, some 2,000km southeast of Tokyo, contains high concentrations of rare-earth elements and yttrium
Japan’s industrial evolution over the next several hundred years has received a major boost with confirmation that millions of tonnes of rare-earth minerals exist just off the country’s coast.
News of the valuable discovery – which potentially frees Japanese firms from costly foreign mineral imports – came on April 10 when scientists from the University of Tokyo and the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) published findings in the UK journal Scientific Reports.
The study said mud from the seabed off the Ogasawara Islands, some 2,000km southeast of Tokyo, contains high concentrations – in some cases nearly 8,000 parts per million – of rare-earth elements and yttrium (REY).
“This REY-rich mud has great potential as a rare-earth metal resource because of the enormous amount available and its advantageous mineralogical features,” the report stated.
Researchers defined a 400 sq km stretch of seabed that they estimate contains 16 million tonnes of rare-earth oxides, including enough yttrium to cater 780 years of domestic demand, 620 years worth of europium, 420 years of terbium and 730 years of dysprosium.
Europium is vital in the development of phosphors and ceramics and has applications in the defence and nuclear sectors. Terbium and dysprosium are also critical in defence technologies, ceramics and advanced magnets.
The research goes as far as to claim the large deposit “has the potential to supply these metals on a semi-infinite basis to the world”.
But a number of hurdles still need to be overcome before the minerals can be put to use – not least the challenge of mining the seabed at depths near 6,000 metres in an extremely remote part of Japan’s exclusive economic zone (EEZ). But the government seems committed to developing the resources.
“Back in 2000, when the dispute between China and Japan over the islands in the East China Sea blew up, Beijing effectively imposed an embargo on rare-earth minerals being sold to Japan, although they denied it,” said Stephen Nagy, a senior associate professor of international relations at Tokyo’s International Christian University.
“These elements are critical for future generations of technology and Tokyo responded by immediately seeking out new sources, including Mongolia, in order to secure shipments and maintain Japan’s technological edge.”
Ideally, however, Tokyo wanted to secure its own resources in order to not be reliant on any other nations for supplies, Nagy said.
Nagy said Japan has invested heavily in scouring the seabed within its EEZ to locate such mineral deposits, and this discovery justifies Tokyo’s efforts to win international recognition for its sovereignty over a large part of the western Pacific, including around the remote atoll of Okinotorishima.
Both China and South Korea have both opposed Okinotorishima being recognised as an island and instead claim it is an atoll that is unable to support human habitation and should therefore not be used to extend Japan’s EEZ.