Vast deposits of rare earth minerals have been discovered on the seabed of the Pacific Ocean amounting to 1000 times those on land, Japanese scientists say.
"The deposits have a heavy concentration of rare earths. Just one square kilometre of deposits will be able to provide one-fifth of the current global annual consumption," Yasuhiro Kato, an associate professor of earth science at the University of Tokyo said.
The discovery was made by a team led by Professor Kato and including researchers from the Japan Agency for Marine-Earth Science and Technology, Reuters reports.
They found the minerals in sea mud extracted from depths of 3500 to 6000 metres below the ocean surface at 78 locations. One-third of the sites yielded rich contents of rare earths and the metal yttrium.
The deposits are in international waters in an area stretching east and west of Hawaii, as well as east of Tahiti in French Polynesia, associate professor Kato said.
He estimated rare earths contained in the deposits amounted to 80 to 100 billion tonnes, compared with global reserves confirmed by the US Geological Survey of just 110 million tonnes found mainly in China, Russia, other former Soviet countries and the United States.
Details of the discovery were published on Monday in the online version of British journal Nature Geoscience.
China, which produces 97% of global rare earth supplies, has been tightening trade in the strategic metal, used in high-tech electronics, magnets and batteries.
The Chinese action has raised concerns globally about supply and triggering jumps in prices.