A massive deposit of rare earth minerals, used to power batteries and high-tech industry, has been found in Japan.
About 6.8 million tonnes of minerals, including dysprosium, have been found - enough to keep Japan's tech industry supplied for hundreds of years.
The find was made in the seabed about 2,000km from Tokyo, near the island of Minami-torishma.
Yasuhiro Kato, an earth sciences professor at Tokyo University, said that the minerals could be a huge boost to the Japanese economy over many decades - possibly centuries.
The deposits were found in Japan's exclusive economic zone, according to the Wall Street Journal.
Currently China produces about 95% of the world's rare earth minerals, and in March Japan joined a trade action launched by the EU and the US after they slowed exports.
The new find could alter that balance - if Japan can find a cost-effective way to get the minerals out. Not only are they very deep beneath the sea (5,600m), the materials are only found in a concentration of about 0.1%, or 1kg per tonne.
New research will be needed in order to safely and cheaply extract the material.
Finding a commercial way to do so could take as long as 20 years, industry insiders told the Journal.
In the meantime the team from Tokyo University intends to return to study the find, and make a detailed survey of the area - which should take about two years.