TOKYO • Work has begun on the new hunting ground for metals in Japan at oceanic depths of 1,600m, about 1,500km from Tokyo.

The country is so devoid of natural resources that most of what it needs has to be imported.

As the island nation has depleted most of its land-based minerals in the post-World War II economic boom, scientists have identified swathes of the sea floor littered with nuggets containing everything from copper to gold - left over from the volcanic activity that created the archipelago millions of years ago.

The trick is extracting them at a profit, something a government consortium will start testing next year.

Ocean mining is not new - Japan began explorations in the 1970s. But new technologies make it easier for firms such as Canada's Nautilus Minerals to collect mineral-rich rock from the sea.

Japanese waters are believed to be home to about 50 million tonnes of ore, and the government wants to revive home-grown supply and ease dependence on imports. When Tokyo hosts the 2020 Olympic Games, bullion for gold medals may come from the deep ocean. "Disruption of metal supplies may occur in the near future," said Dr Tetsuro Urabe, a geologist who is the director of the government's Next-Generation Technology for Ocean Resources Exploration Programme.

"We don't want to be in a panic when we are confronted with a copper crisis. Unless we develop various kinds of new technology in advance, we won't be ready for launch when needed."

It is not surprising that mineral resources sit untouched in deep waters around Japan.

The country is nestled in the Pacific Basin, along a line of volcanoes and fault lines known as the "Ring of Fire". It is a region prone to earthquakes and eruptions, and when volcanic activity occurs in the sea, magma pushes up from the earth's crust.

After it cools, the deposits contain minerals in far greater concentrations than those dug up on land.

Engineers have used remote-controlled robots and special sensors to search the deep-sea floor for the most promising deposits.

As the world's third-biggest economy and a major importer of everything from iron ore to oil, Japan wants to exploit its rights to access sea-based mineral ores that one domestic industry group estimates may be worth 80 trillion yen (S$1.1 trillion). Under international maritime law, Japan holds sway over the area 200 nautical miles from its shores in what is the world's sixth-largest exclusive economic zone.

A Japanese consortium led by Mitsubishi Heavy Industries and Nippon Steel & Sumitomo Metal Corp's engineering unit will conduct pilot mining and ore lifting on deposits at the Izena sea hole in the area off the southern island of Okinawa in the next financial year starting April.

Japan has said the deposits have about 7.4 million tonnes of ore, twice the amount that was detected just three years ago.

"New deposits have begun to be found one after another," said Mr Mitsuya Hirokawa, deputy director-general at the metals mining technology department of Japan Oil, Gas & Metals National Corp, the state-run firm that helps secure energy and mineral supplies and is providing support for the seabed venture. The area off Okinawa shows some of the "greatest potential," Mr Hirokawa said.

But such ventures are not without risks. Metal prices plunged last year, forcing mining firms to cut capital spending and close mines.

There is also politics. The site off Okinawa is near waters claimed by both Japan and China, which are feuding over islands called Senkaku in Japanese and Diaoyu in Chinese.

But Japan cannot afford to miss out on accessing seabed minerals, said Mr Takashi Sakamoto, general manager of the submarine resource business department at Nippon Steel's engineering unit. "Japan is two laps behind others in the ocean oil market, so it would be very sad if the same thing happens when we try to work on undersea mineral resources," he said.

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