Underwater Resources: Treasure at the Bottom of the Sea
The global economy could soon be getting its supply of raw materials from the deep seabed, where copper, zinc, cobalt and gold lie hidden in black smokers and manganese nodules. As the prices of land-based natural resources rise, new technologies including remote-controlled underwater vehicles might soon be crushing undersea rock containing metal ores and pumping it to the surface.
When Peter Herzig talks about his research, he sounds as though he were describing an early 20th-century industrial zone, complete with smokestacks and ore processing plants spewing toxic heavy metals, including cadmium, arsenic and lead.
Herzig, a geologist, specializes in the study of one of the most unusual deep-sea geological formations: so-called black smokers. The chimneys, two to five meters (about 6-16 feet) tall, were first discovered on the ocean floor in 1977. Boiling hot water, with large amounts of copper, manganese, nickel and gold originally contained in rock, shoots from the chimneys' openings. As the hot liquid enters the cold water deep in the ocean, the metals it contains are deposited onto the surrounding ocean floor.
So far bacteria have been the beneficiaries of the boiling discharge. At temperatures exceeding 350°C (662°F), specialized single-cell organisms consume the precipitated metal sulfides, possibly emulating a process the first living beings performed when the earth was still young and temperatures were much higher.
But if Peter Herzig has his way, humanity will soon join in this exploitation of Neptune's treasures. "The black material contains almost everything our industrial society craves," says the scientist. Copper for the electronics industry, nickel and zinc used in steel mills, indium for flat-screen displays -- even gold for national skyrocketing reserves.
Last week, Herzig hosted geologists, mining engineers and chemists at a conference of the "Underwater Mining Institute" in the northern German port city of Kiel. "There is a sense that something big is about to happen," whispers the director of the IFM-Geomar Oceanographic Research Institute during a presentation. His optimism is timely, especially with prices for raw materials skyrocketing in the booming global economy.
- The price of a ton of copper, for example, jumped from $2,000 in the late 1990s to $8,700 this year.
- In the same period, the price of a ton of zinc went from $1,000 to almost $4,000.
- The price of indium has increased tenfold within just a few years, with existing resources expected to be exhausted by 2013.
"This is exactly the right time to begin underwater mining," says Richard Garnett. The 70-year-old Briton gazes serenely through the rectangular lenses of his engineers' glasses. He still remembers a time, about thirty years ago, when his profession was in uproar over another potential boom. Back then, manganese nodules mined at 6,000 meters (19,686 feet) below sea level were seen as the magic bullet that would solve the world's raw material problems.
Germany's Preussag company was one of the companies that soon began recovering the nodules, which contain metal ore, from the ocean floor, bringing about 800 tons to the surface for research purposes. Garnett, for his part, founded a company that ran a gold mining operation in the shallow waters off the coasts of Namibia and Alaska until the 1990s.
But then precious metal prices went south, taking his company with them. "We still have no efficient and robust mining technology for great depths," Garnett says by way of a warning to all those who look to the oceans as industry's next bonanza.
And yet, all skepticism aside, even Garnett sees signs that the latest venture into the deep seas could work this time around. "We now have a combination of high raw material prices and tremendous advances in mining technology," says Garnett. The oil industry, which is drilling at ever-increasing depths, is principally responsible for development of the new technology. In addition, remote-controlled underwater vehicles, which essentially eliminate the need for a human presence on the ocean floor, make production a far less daunting proposition.
Satellite navigation, Garnett adds, is also an important factor. "In the past, we had to look to the stars to find our way back to the same mining site," says Garnett, and the expression on his face reveals just how often this approach wasn't entirely successful. "Nowadays, thanks to GPS, we can find our way back to precisely the same spot."
At this point, the industry is still involved in commercial mining efforts in shallower waters. De Beers, the world's largest diamond company, is currently prospecting for shimmering treasure in the porous sediments off the Namibian coast.
The South African company uses German technology in its underwater project. Wirth, a company based near Cologne, supplies De Beers with devices known as underwater crawlers. "They're essentially milling devices that are used to break up the layer on the sea floor," explains Wirth manager Peter Heinrichs. The crushed rock is then pumped up to a waiting ship.
According to Heinrichs, the process is astonishingly efficient. "The 47-man crew on board can mine as many diamonds as 3,300 mine workers on land," says Heinrichs, adding: "The cost of the ship, 70 million, is amortized within two years."
Heinrichs hopes to receive approval by the end of next month for the underwater testing of mining equipment that can also operate at depths of 2,000 meters (6,562 feet). "Operating a hammer at 200 bars of pressure is no small task," says Heinrichs. Nevertheless, he is convinced that "the future of the raw material supply lies in the ocean." The test phase for Wirth's new equipment could be completed within three years, at which point, the company hopes, oil and mining companies will be using its technology to exploit what some believe is an El Dorado on the ocean floor.
Nautilus, considered a pioneer when it comes to mining for metal near black smokers, could become one of Wirth's first customers. David Heydon, the CEO of the Australian-Canadian company, was unable to attend the conference in Kiel, citing important talks with investors. When Placer Dome, a major mining corporation, decided to invest in Nautilus's venture this spring, the company dispatched a drilling ship to the Bismarck Sea off the coast of New Guinea.
The local government has granted Heydon the mining rights for an area where he plans to begin breaking apart black smokers by mid-2009 at the latest. Based on drilling tests, he expects the site to yield about two million tons of copper. Using a device called a drum slicer, he plants to crush the metal-containing steles on the ocean floor and then pump the material to the surface. "The device will resemble a pureeing rod with a built-in pump," says Heydon. He has already been in talks with Voest-Alpine Bergtechnik, an Austrian manufacturer of mining equipment, which could supply the devices he envisions.
Although it may sound a bit like a Jules Verne fantasy, Heydon's plans are in fact based on strictly rational calculations. While the rock in the remaining copper mines on land rarely contains more than one percent of the sought-after metal, the material ejected by black smokers has at least a ten-percent copper content. Setting aside issues of economic attractiveness, exploiting the underwater formations also has environmental benefits.
"Copper mines, in the Andes, for example, destroy the landscape, displace the local population and are devastating to the region's social framework," says the Australian. But, says Heydon, marine copper mining would be essentially local, the pumps would capture most of the dust churned up by the equipment, and living creatures would soon return once the equipment was removed.
Environmental organizations do not share the Nautilus CEO's optimism. They consider the ocean floor part of mankind's common heritage, and believe that it ought to be protected against industrial greed. Many scientists have also voiced doubts about underwater mining. But they are not as concerned about inactive black smokers as they are about manganese nodules.
In addition to manganese, these coconut-sized objects, buried in the sludge at great depths in the Atlantic and Pacific Oceans, contain metals like copper, zinc and nickel. Although they can be collected with a device similar to a rake, the process churns up huge clouds of dust. Because of deep-water currents from the Antarctic regions, it takes a long time for these underwater dust clouds to settle. In a 1989 test, the raking process virtually wiped out most residents of the ocean floor, including bristleworms and small crabs.
It takes a million years for manganese nodules to grow by four or five millimeters. BGR researcher Hermann-Rudolf Kudrass estimates that harvesting the fruits of these geological processes would yield about 45 million tons of nonferrous heavy metals.
But some in his agency doubt whether this metallic fortune will ever be gathered from the floor of the Pacific. Nevertheless, Kudrass remains determined to pursue his treasure. "As of this summer," says the geologist, "Germany's dearth of raw materials is a thing of the past."
Translated from the German by Christopher Sultan
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