TOKYO Vast deposits of rare earth minerals, crucial in making high-tech electronics products, have been found on the floor of the Pacific Ocean and can be readily extracted, Japanese scientists said on Monday.
"The deposits have a heavy concentration of rare earths. Just one square kilometer (0.4 square mile) of deposits will be able to provide one-fifth of the current global annual consumption," said Yasuhiro Kato, an associate professor of earth science at the University of Tokyo.
The discovery was made by a team led by Kato and including researchers from the Japan Agency for Marine-Earth Science and Technology.
They found the minerals in sea mud extracted from depths of 3,500 to 6,000 meters (11,500-20,000 ft) below the ocean surface at 78 locations. One-third of the sites yielded rich contents of rare earths and the metal yttrium, Kato said in a telephone interview.
The deposits are in international waters in an area stretching east and west of Hawaii, as well as east of Tahiti in French Polynesia, he said.
He estimated rare earths contained in the deposits amounted to 80 to 100 billion tonnes, compared to global reserves currently confirmed by the U.S. Geological Survey of just 110 million tonnes that have been found mainly in China, Russia and 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.
The level of uranium and thorium -- radioactive ingredients that are usually contained in such deposits that can pose environmental hazards -- was found to be one-fifth of those in deposits on land, Kato said.