Mining's Final Frontier
Begley, Sharon, Newsweek
Byline: Sharon Begley; With Isaac Stone Fish in Beijing and William Underhill in London
A new generation of prospectors is eager to explore the ocean floor. Will deep-sea digging damage one of the earth's most valuable ecosystems?
Having ventured to Australia to buy a coal company for $3.1 billion, to Guinea to lock up access to aluminum and diamonds and gold, and to Iraq to insure a big share of that country's expected postwar oil production--all last year--Chinese companies and government-supported funds have shown that they will go to the ends of the earth to acquire the resources needed to stoke their country's industrial growth. Now China is angling to be first to exploit a source of minerals that has tempted and frustrated dreamers for almost 150 years: the floor of the deep sea.
In May an arm of the Chinese government submitted plans to explore the seafloor around an underwater ridge in the Indian Ocean near Madagascar, where hot springs in the ocean bottom called hydrothermal vents have created deposits containing gold, silver, copper, nickel, cobalt, and tellurium (used in computers, CDs, and DVDs). The filing came on the first day that the International Seabed Authority, the United Nations agency set up to manage seafloor mining in international waters, accepted exploration plans; as land-based sources of precious metals run dry, China will surely have company. It is no small irony that the first would-be undersea '49ers made their move in the midst of BP's Gulf of Mexico disaster, but not for the reason one might think. Just as the reality of the BP spill has, so far, fallen short of the marine Armageddon some green groups predicted, so the actual environmental damage from mining the seafloor looks as though it might, too. If so, nothing is likely to stand in China's way as it stakes its undersea claims.
The environmental concerns arise from one of those coincidences that makes you wonder about nature's sense of mischief. The richest lodes of undersea minerals are located at hydrothermal vents. Here, volcanic activity beneath the earth's crust sends sulfur-rich plumes spewing up from gashes in the seafloor into the ocean, where the plumes support unique ecosystems of animals and microbes. Discovered in 1977, these communities aren't directly based on sunlight and photosynthesis like every other ecosystem on earth, but on the chemicals in the plume. Microbes turn the chemicals into energy and biomass, larger creatures eat the microbes, and the result is exotic animals like red-tipped tubeworms that have neither mouth nor stomach, as well as anemones, giant red-fleshed clams, jellyfish that resemble dandelions, shrimp, snails, lobsters, and blind white crabs--different combinations of species at each vent.
Since 1977 more than 1,300 species previously unknown to science have been discovered at the vents. "We go back to a site dozens of times and find new species routinely," says marine biologist Cindy Lee Van Dover of Duke University. The vents may also be where chemistry first became biology--that is, where life on earth began--and thus be scientifically priceless.
In 1979 scientists discovered that the same plumbing that supports the bizarre menageries also creates the mineral deposits that China is eyeing. Magma under the ocean floor heats seawater circulating through rocks above it; the heat causes gold, silver, copper, nickel, zinc, and other metals in the rock to leach into seawater that has percolated miles down through the seafloor crust, explains marine geologist Peter Rona of Rutgers University. The heat then propels the seawater (now as hot as 750 degrees Fahrenheit and full of dissolved metal sulfides) back up through the crust, where it meets colder water. The shock of the cold makes the metal sulfides crystallize. The result: "seafloor massive sulfide deposits" that are rich in valuable metals.
"Massive" is an understatement. One deposit of copper, iron, zinc, gold, and silver sulfides in the Atlantic is, at 600 feet across and 120 feet high, as big as the old Houston Astrodome. …