Undersea Riches.

Daylight slowly fades as the tiny submarine descends beneath the Atlantic Ocean. One thousand feet below, the sea is pitch-black. Even with the sub's powerful lights, visibility is a mere 20 feet. Two hours later, Rutgers University marine geologist Peter Rona and his two-man crew settle down on a high mid-Atlantic ridge, one mile below the surface.

The outlandish marine life--giant white clams, mounds of intertwined spaghetti-like worms, and forests of tubular, human-size creatures swaying in the current--fascinates Rona. "It's otherworldly, like nothing I've ever seen before," he says.

But something else captures Rona's attention. Clusters of slender "chimneys" belch what seems to be black smoke. Most of these chimneys, or "black smokers," rise just a few feet from the seafloor, but several rock formations loom more than 30 meters (100 feet) high. Black and brown, the chimneys glitter with metallic red, orange, and green deposits on their sides. The mineral deposits that form the chimneys are mega-rich in some of Earth's most prized metals: gold, copper, silver, and lead--metals used in everything from fine jewelry to water pipes, telephone lines, and medical equipment (see mineral table).

MINERALS TABLE

Mineral       Gold                     Lead
              (Au)                     (Pb)

Used For      jewelry, spacecraft      batteries, water
              coating, electronics     pipes, gasoline
              coins                    crystal

Found         South Africa, U.S.,      U.S., Australia
              Russia

Cool Facts    Your contains about      The glass screen on
              0.001 grams of gold      your TV contains
              for every kilogram       about 0.23 kg (0.5
              you weigh.               lbs) of lead

Mineral       Silver                   Copper
              (Ag)                     (Cu)

Used For      dentistry, coins,        pipes, wires, the
              photography chemicals    Statue of Liberty's
                                       "skin"

Found         Canada, Mexico,          U.S., Northern
              Norway, Czech            Europe
              Republic

Cool Facts    Silver iodide can be     Copper paint on
              sprinkled over           ships' hulls kills
              clouds to produce        small marine
              rain.                    organisms

GOLD RUSH!

The discovery of untold treasure on the ocean floor has sparked a kind of millennium-style gold rush. But unlike the rush of prospectors who flocked to California in 1849 with pickaxes on their backs, scientists now scour and map seabeds in subs equipped with remote-controlled cameras. In 1998, geologists discovered a trove of gold and silver--its worth estimated at $2 billion!--in the crater of an active undersea volcano 400 kilometers (250 miles) south of Tokyo. And that has Peter Rona and many other scientists concerned.

As miners stake claims to sites of undersea riches, environmentalists worry that seabed mining could destroy the ocean's deep exotic life (see sidebar "Extreme Life"). No international mining regulations exist for this new industry--only the regulations of individual countries within their own coastal waters.

"We've only recently discovered many of these species," says Rona. Some scientists who study these environments think they may be the birthplace of all life on Earth. "If we lose them, we lose valuable secrets to the history of evolution."

But the gold rush is gaining momentum fast. Marine geologists have uncovered mineral-rich volcanic fields in the Pacific, Atlantic, and Indian oceans. Getting at these riches, however, will cost mining companies a fortune. Geologists and engineers will need to develop new technologies to haul the black smokers to the surface so they can extract the precious metals embedded in them.

BLACK SMOKERS

Black smokers are created by undersea volcanic hot springs (see diagram). The chimneys rise from underwater volcanic vents, or fissures, in the Earth's crust. Magma, mineral-laden liquid lava, percolates from the vents at temperatures up to 400 [degrees] C (752 [degrees] F). Highly concentrated minerals called polymetallic sulfides harden into ever-growing chimneys as they hit icy sea water. Since 1977, more than 100 hot springs have been discovered along a 64,000 km (40,000-mi) chain of volcanic fissures that circle the globe like a gold ring.

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The new gold rush kicked off in 1997, when Papua New Guinea granted a private Australian company, Nautilus Minerals Corporation, permission to prospect for minerals off its coast. The mineral deposits lie in relatively shallow sea water, about a mile down. Some small samples of volcanic rock contain up to 200 grams (7 ounces) of silver and 28 gm (1 oz) of gold per ton, higher than some mineral deposits found on land. Nautilus plans to start hoisting up a wider sampling of volcanic rock from the seafloor within a year.

But mining undersea metals even from shallow waters demands technological wizardry. The formations off Papua New Guinea lie in frigid darkness. Even at one mile deep, the literally crushing water pressure is between 3,000 and 5,000 pounds per square inch. "The pressure can press a car into a little block of metal," says geological engineer J. Robert Woolsey. So how will Nautilus geologists bring up these riches?

MINING THE DEPTHS

Scientists are currently locating and mapping mineral-rich undersea volcanic fields. They use high-tech sensing tools dangled on cables from a ship to the seafloor to identify what minerals exist in each volcanic field. Sonar, or high-frequency sound waves, creates 3-D images of seafloor geography. Seismic waves, or low-frequency sound waves, penetrate the ocean bottom, measuring the depth of potential mineral deposits. Magnetometers measure the amount of magnetic material in rocks, and chemical detectors detect mineral compounds.

But new technologies must be invented to haul up to 450 kg (1,000 lbs) of rock and sediment from the ocean floor each day. These methods must protect the exotic residents of the little-studied ecosystems (complex communities of organisms). One option, Woolsey explains, is to use small remote-controlled "crawler vehicles." Designed much like tiny tanks, they could collect, crush, and suck large mounts of rock to the surface through a hose, or "umbilical cord," to a processor ship. There, minerals would be extracted from the rock in ways traditionally used by land miners--using chemicals or hot water.

Another scenario is for a series of huge buckets on conveyor belts to hoist up the wealth. Robotic Autonomous Underwater Vehicles, or AUVs, capable of descending to 6,100 meters (20,000 feet), might be used as scouts, with video cameras for eyes. "We might have a whole flock of these working off a single ship," says Woolsey.

Before Nautilus commences mining, the government of Papua New Guinea demands the company produce an acceptable plan to protect the undersea environment, possibly creating special marine reserves. As natural mineral deposits diminish on land, Earth's exploding population will need additional mineral resources in the 21st century. The possibility of plucking a virtual treasure chest of gold and silver from the bottom of the sea is irresistible. Miners hope it will yield a gold mine of rewards.

RELATED ARTICLE: EXTREME LIFE

Blind shrimp, mammoth white clams, brown hairy snails--they're among 300 species that marine biologists have discovered in the last 20 years. They thrive around deep-sea volcanic hot springs. "From preliminary studies, volcanic fields seem to be as rich and abundant with life as rainforests" says Peter Rona, a marine geologist at New Jersey's Rutgers University. Rona worries that proposed ocean mining could devastate this newly-discovered life before scientists get a chance to fully study it.

Some discoveries have shocked scientists, like a long-necked barnacle thought to have died out with dinosaurs 65 million years ago. Heat-loving microbes called hyperthermophiles grow in the walls of undersea vents. And small forests of tube worms resemble lipsticks, with red "heads" that stick out from white tubes.

How have these animals survived on the ocean floor? In most sea environments, the primary source of energy is sunlight, but a mile or more down, ocean waters are pitch-black and freezing. In theory, little should survive. Instead, creatures here are fed by sulfur compounds from the hot springs.

What's more, they can withstand searing heat and intense deep-water pressure. They even survive strong earthquakes that frequently rumble across volcanic fields. The big question: Can rich, exotic undersea life withstand the violent impact of human undersea mining?

RELATED ARTICLE: HOW "SMOKERS FORM"

1. Earth's outermost layer or crust is divided into large, solid tectonic plates that resemble a cracked eggshell. These plates move on top of the Earth's soft mantle, which lies between its crust and core.

2. Molten lava rises from the mantle and escapes through cracks between the plates, forming undersea mountain ranges.

3. Seawater fills these cracks and, heats up, and rises through vents as hot springs, rich in dissolved minerals and metals.

4. Icy water sinks beneath Earth's crust, where it's heated by molten rock. Hot water shoots up through the vents.

5. Water comes out of chimney at about 350 [degrees] C (662 [degrees] F

6. As hot mineral-enriched water mixes with icy seawater, mineral particles build up the chimney.3