Oceanography: Mining Minerals In The Ocean

Science screen report is provided to the schools of Baltimore by Martin Marietta Corporation. Heat. [Music] The sea, a new reserve. reserve of global resources, including metals from deep sea nodules, potato- sized objects covering thousands of square miles of seab bottom. To learn more about nodules, their origins, process of growth, distribution, and other factors, a major deep ocean and land-based research program was carried out. At the same time, to determine if deep ocean nodules can be mined, the first self-propelled, remotely controlled robot miner was tested 3 miles under the Pacific Ocean. This is the story of those two projects. [Music] This is a deep sea nodule, a potato- sized lump holding over 30 metallic oxides. Millions of tons of such nodules lie scattered on the deep ocean floor. [Music] The electron microscope reveals its porous crystalline structure which accumulates layers of manganese, copper, iron, and cobalt. [Music] A cross-section suggests it grows around a pebble or shark's tooth or other seed. While growth is incredibly slow, perhaps 4 thous0th of an inch every million years, sizable nodules now cover thousands of square miles of seabed. Mysteries surround the nodules. Why aren't they buried by sediments? Why do nodules concentrate particular metals at particular rates? How do they grow? Why should they exist at all? To answer these questions, the National Science Foundation used the research vessel Melville to carry out intensive studies of selected sites on the Pacific Ocean seabed. [Music] Arriving at one study zone, the crew lowers sound beacons to the seabed, creating a 10mi square navigation grid. [Music] Next, a one-tonon robot mapping vehicle or fish employs an echo sounder, magnetometer, sound hydrophone, and sonar to gather scientific data about the test zone. In the control room, the deep toe team monitors the robot sensors on chart recorders. The sound beacon signals are picked up and computer processed to give its position. The ship's own course, speed, and location are plotted by satellite. As ship and robot cross and recross the study zone, the chart becomes crowded with course plots. The robot carries three still cameras and one TV camera which uses strobe lights and cruises 35 ft off the seafloor. Its pictures are studied by the team members planning the next step in the research actual sampling of the seafloor. [Music] On deck, the first box corer on its massive A-frame begins its 4-hour round trip to the seabed for the purpose of gathering sample nodules. At last, the box corer is safely on deck again and sea water drained away. It is designed to transport both nodules and their environment, preserving even their seabed orientation. A variety of scientists are on board. Geocchemists measure trace element levels both in sediments and in fluids running through them using this dialysis stake. Because the minute quantities may deteriorate, the substances are also measured now with a rebuilt blood gas analyzer. [Music] One geologist is investigating biotic structures, life forms on the nodule surfaces, which suggest nodules may grow in a manner similar to coral reefs. A chemist studies the water associated with the samples, the poor fluids. Perhaps these poor fluids, then rich in metals, were carried down to the seabed in sediments. Then those metals were somehow deposited on the nodules. [Music] Meanwhile, piston corers carry out deep probes of the supporting seabed, taking cross-sections of sediment depositions going back millions of years. The core sections are later indexed and stored for study, part of the global scientific deep sea core bank. After [Music] 2 weeks, a significant part of the study zone's bottom topography and surrounding waters have been charted, sampled, and packed into storage. [Music] At Voyager's End, over 50 research centers worldwide will take part in studies of this scientific treasure trove. [Music] Meanwhile, exploration ship Governor Ray monitors a sea mining research site, part of a separate program conducted elsewhere in the Pacific. Such environmental responsibility is considered basic to future ocean mining. This project's surface platform ship is the Glowar Explorer, notable for a complete onboard internal dry dock, which now holds the advanced design robot miner, ready for testing. 45 ft long, 30 ft wide, and 15 ft high, it's about the size of a small house, a product of 16 years of research and development. It moves across the treacherous seafloor using an Archimedes screwdriver principle. Its eyes and ears are special TV and sonar systems. Their images, computerenhanced, appear in the ship's mining control room. Its nodule collector tested on a simulated seafloor embedded with nodules crushes them into gravel then conveys this to a processing section. An airlift system injects air bubbles into the mixture or slurry of seabed materials which is then pumped to the surface as simulated here. [Music] Arriving on station, Glomar Explorer drops her seabed sound beacons. Their signals, plus wind, wave, and tide data, are used by computers to operate the ship's bow and stern thrusters, so to keep it locked over one location. [Music] As launch day approaches, critical checks are made, chocks removed, work platforms hoisted out, and dry dock thoroughly cleaned. Water pressure in the dry dock must equal the ocean's pressure before the doors are opened. During the 8 hours needed to fill it, final checks are completed. At last, the doors open. It's three miles to the bottom. A team of divers make the final systems checks. As the robot miner hangs60 ft under the ship, just below her circular nodule processing section, pipe attachment begins. It is by way of these 60 foot long 20tonon pipe sections that miner and processor are lowered to the seabed and slurry return to the surface. The ship's heavy lift derek system keeps ship motions from affecting the growing pipe column. Fully extended, the pipe is 3 m tall and weighs 3500 tons. Lowering it is an exacting 130hour job. [Music] 5 days later, the miner accurately positioned. Its processor is joined to it. Both respond well to all commands, proving highly maneuverable, easily turning corners and smoothly traversing the hilly ocean terrain. In fact, deep sea mining has advantages over onshore mining. Nodule deposits are easily found and estimated without tedious prospecting. Extraction is done without digging, explosives, or tunnel networks. [Music] Both sonar and TV images and the excellent minor responses suggest nodules may be collected as easily as a combine harvests fields of grain. [Music] Much testing and pilot plant operations still lie ahead. A commercial miner would be about 10 times the size of the test robot. Its support ship eight times as big as the Glowar Explorer, about three football fields long. Processing systems must also be scaled up. Three other challenges remain. Environmental impacts, economics, and law of the sea considerations. Deep sea nodules continue to hold many scientific mysteries. But with deep sea mining engineering now feasible, they also promise a way to meet resource needs for centuries. [Music] [Applause] [Music] This science green report was provided by Martin Marietta Corporation. Martin Marietta is proud of its historic and diversified presence in the Baltimore area and is pleased to be able to contribute this excellent film series for use in Baltimore's schools.