Photo/IllutrationA layer of cobalt-rich ferromanganese crust at a depth of about 5,500 meters (Provided by the Japan Agency for Marine-Earth Science and Technology)

For the first time at such extreme depths, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has discovered a layer of valuable cobalt-rich ferromanganese crust 5,500 meters beneath the ocean.

Cobalt-rich ferromanganese crusts are found on the slope of seamounts, or underwater mountains, covering their surfaces with layers usually measuring several centimeters in thickness. The sediment is considered to be rich in rare earth elements, including cobalt and platinum.

Before the latest research, such mineral-rich crusts were believed to exist only in much shallower waters, on seabeds no more than 3,000 meters deep.

Based on this theory, the cobalt-rich ferromanganese crusts in waters around the nation were believed to contain elements worth 100 trillion yen ($884 billion) in total.

However, the new discovery means the deposits add up to a far greater value.

“There may be more than double the amount of what we had previously estimated,” a member of the research team said.

Using a remotely operated underwater vehicle, the research team collected cobalt-rich ferromanganese crusts from a seabed about 200 kilometers southwest of Minami-Torishima island. The uninhabited islet is located about 1,900 kilometers southeast of Tokyo.

The team will be studying the 80-kilogram sample it extracted to see how much natural resources it contains, as part of a large-scale government project dubbed “Zipangu in the Ocean.”