Last month Waseda University and the University of Tokyo announced a joint team had sampled potentially huge deposits near one of the Ogasawara islands, 1,500 miles southeast of the Japanese mainland.
Frances Wall, a professor of applied mineralogy at the University of Exeter's Camborne School of Mines, said rare earths were critical to production of a number of industrial goods, from smartphones to missiles and until recently the only supply had come from China.
"In 2011 there was a crisis when China threatened not to export as many of them and that led to a lot of rare earth explorations. Most have stopped now. Japan in its car manufacturing and other technology is a big user of rare earths but they don't have the right sort of rock on land so their geologists started to look all over the world and this one team began to look at the sea floor," Professor Wall told Sputnik.
The Japanese researchers estimated there was 16 million tonnes of rare earths in the sea near Minamitori Island, including enough terbium to last 420 years and enough europium to last into the 27th century. Terbium is used in motors and europium is used to produce liquid crystal displays. They also found samples of dysprosium and yttrium, which are used in the production of industrial magnets.
"Rare earths are a group of 17 elements, although in practice we talk about 15 of them. China dominates supply, producing 87 percent of light rare earths and 100 percent of heavy rare earths," Professor Wall told Sputnik.
She said the term rare earths was misleading.
"The name is because of how difficult they are to separate from each other, rather than because of their rarity. There are many other rare earth deposits around the world which are land-based. There is no shortage under the earth. Cerium, for example, is as abundant as copper," Professor Wall told Sputnik."If you are manufacturing something you want pure terbium or pure neodymium but in nature these elements always go together, which is the difficulty," Professor Wall told Sputnik.
She said there were ethical questions about the amount of toxic waste produced by China in mining for these rare earths.
"There is no doubt the Chinese have not been environmentally responsible and there has been contamination but we are all using their rare earth in our phones and tablets every day. The Chinese are trying to clean up their act but it's a huge task," Professor Wall told Sputnik.
She said that in recent years two suppliers — Lynas, from Australia and Rainbow Rare Earths from Burundi — have started producing rare earth elements which they claim are more ethical and environmentally responsible than their Chinese competitors. But Professor Wall said it was unclear yet whether manufacturers were willing to pay extra for ethically produced rare earths in the absence of any consumer campaigns.
In recent years other campaigns have highlighted the ethics of "conflict diamonds" and coltan — a mineral from war zones in the Democratic Republic of Congo which is used in the manufacture of smartphones. She said another campaign had been launched recently to make consumers aware that much of the cobalt used in batteries is being produced in the DR Congo using child labor.
Professor Wall said the rare earths discovered off the Japanese coast were about three miles down on the ocean floor.
"We know nothing about mining this sort of stuff from the ocean floor and if you think of all the work they would need to do to make sure it's environmentally-friendly, I think it's a long way off from production," Professor Wall told Sputnik.
She also pointed out that the estimates which had been mentioned in the scientific journal article last month were not the same that as those that investors would require."When you are looking for ore deposits and want to raise money from investors there are very strict codes you have to follow before you can give figures. The Japanese team have not released a resource deposit yet," Professor Wall told Sputnik.