cold fjord writes: It looks like deep sea exploration may pay off big time as Japanese scientists have located rich deposits of rare earth elements on the sea floor in Japanese Exclusive Economic Zone waters, following up on their find two years ago of huge deposits of rare earths in mid-Pacific waters. The cumulative effect of these finds could significantly weaken Chinese control of 90% of the world supply of rare earth metals, which the Chinese have been using to flex their muscles. The concentration of rare earth metals in the Japanese find is astonishing: up to 6,500 ppm, versus 500-1,000 ppm for Chinese mines. The newly identified deposits are just 2-4 meters below sea floor which could make for relatively easy mining compared to the 10+ meters they were expecting... if they can get there. The fact that the deposits are 5,700 meters deep means there is just one or two little problems to resolve : "A seabed oil field has been developed overseas at a depth of 3,000 meters. . . But the development of seabed resources at depths of more than 5,000 meters has no precedent, either at home or abroad. There remains a mountain of technological challenges, including how to withstand water pressure and ocean currents and how to process the mining products in the ocean, sources said."