Oceanography at Work: Diamonds Under the Sea

[Music] the coast of Southwest Africa is an unforgiving land of Stark rocks and wander ing Dooms its Shores are pounded by great Breakers and swept by Cold currents its weather alternates between wind and fog and Blasting Sun it has but one Saving Grace there are [Music] diamonds these graceful Canyons were sculptured Beneath the Sea many thousands of years ago by moving water armed with abrasive Sands and gravels the gravels contained diamonds and when the ocean level receded the gravels were left behind now that they have been removed by mining the strange shapes of these ancient undersea canyons are revealed in other parts of the mine the old sea floor was nearly flat and after the main part of the diamond gravels have been removed by machines native sweepers carefully clean the cracks in the Bedrock [Music] occasionally they find greasy bits of hardened fire Diamond [Music] crystals are there similar deposits on the present ocean bottom Brit Brock and Willard baskam plan an expedition to find out the casa Coast is a small freighter converted for geophysical work it leaves Cape Town's beautiful Harbor and heads North to the diamond Coast where it will probe the seaf Flor with sound to determine the thickness of the undersea gravels and the shapes of the Rocks beneath once outside the harbor the ship felds the Great South Atlantic swell and begins to Buck it will be a rough trip but happy purposes alongside of the traditional sailor's Omen of a lucky [Music] Voyage the sun sets but the captain remains at his post knowing that many a vessel has been wrecked on this dark coast and that only the Vigilant Will [Music] Survive the following morning the geophysical equipment is launched first spark gap is streamed behind the ship when a high voltage electric current surges through this cable a spark leaps the Gap creating a small explosion and then a hydrophone which listens for The Echoes of those explosions from the undersea rocks is put overs side the hydrophones trail well behind away from the noise of the ship on a cable that is bued up by a plastic hose [Music] in the ship's laboratory the spark generating equipment is [Music] started each time the spark jumps here a similar one jumps at the end of one of the cables and radiates a pulse of sound the hydrophone at the the end of the other cable detects The Echoes from the various undersea [Music] layers thus the rock structure is recorded the flowing paper is periodically examined and the instrument settings adjusted to give the best results that pair of cables will follow the ship for 10,000 km as it goes back and forth in and out along the desert Coast where Dunes rise hundreds of feet from the sea and shifting underwater sandbars are an extra Hazard that keeps the captain constantly on the [Music] bridge often the work continues after dark when a technician makes the final marks on a chart and takes a blow for study in the onetime cargo hold two geologists examin the record for evidence of gravel deposits and for undersea features like the ancient sea cliffs and canyons seen ashore the dark lines are the recorded Echoes of rocks buried beneath sea and sediment but determining exactly what the Echoes mean is not a simple matter it requires thoughtful geological interpretation are the diamonds it's much too soon to say our search has just begun determining the thickness of the undersea gravel beds is only half the geophysicist problem he must also know the ship's position precisely so that a chart can be made of any deposits that are discovered precise position at Sea requires survey points on land and so a Shore party starts out across the trackless desert in Land Rovers their job is to find the old survey monuments and check their positions [Music] they resurvey each point and then they push on across the [Music] Wasteland at each Monument a radar Beacon is set up an electronic package that shines like a lighthouse on the ship's radar the shore party leader radios to the ship our Beacon is operating do you see it the ship's radar antenna scans The Horizon bright and clear answers the radio operator on the ship okay on to the next [Music] one there are various hazards but these are a normal part of desert [Music] operations and so the shore party moves steadily up the coast leaving behind a trail of electronic [Music] monuments each Beacon makes a bright spot on the ship's radar screen with this equipment the ship's position can be determined within a few feet in an adjacent room on the ship the automatic position plotter is set up on a chart of the coast the position of the needle is controlled by the radar so that it traces a ship's motion on the chart the operator adjusts the range rings on the radar scope until they exactly coincide with the bright spots made by the beacons onshore then the distance to the beacons can be read directly every 3 minutes the operator pushes a button and the ship's position is pricked into the chart beyond the old monuments new survey lines must be run across the desolate Namib Desert the skeleton Coast is a hard country inhabited only by the ghosts of diamond miners who worked here before World War I in those days this Camp was supplied by camel and oxen the only way of crossing the desert but now we use a helicopter the Skylar but the helicopter cannot operate alone its fuel must be brought in by another aircraft and so the party radios for a small rugged cargo plane called the beaver to bring in gasoline and supplies for emphasis they spell out the message in beer bottles and Survey Flags send the beaver and the Beaver comes it takes off from a desert air strip circles above a mirage zooms out across the coast of Southwest Africa north it flies along the Great Wall of sand where camel Supply trains were ever in danger of being trapped against the Steep sand slope by a rising tide it flies over the breakers and sandb bars and lagoons over a flight of white [Music] pelicans and over a herd of gsach the great desert [Music] antelope Beaver buzzes the camp to alert the party before a lighting on a vast natural airport where no plane has ever before landed and now with plenty of fuel Skylark can go where it pleases over the Namib sea of sand the surveyors are but tiny dots on the vast Dunes entirely dependent on the helicopter for life but it is doubtful that a man could walk out of this desert alive if it failed to appear a theodoly is set up to measure the angle between the last survey point and the one ahead neither would be visible except for a flash of sun reflected in a mirror [Music] the angle between the distant points is measured and recorded the telomer is an electronic tape measure it measures Distance by measuring the time for radio waves to travel between a pair of [Music] instruments [Music] when the measurements are completed the helicopter goes back to pick up the second survey party then it Leap Frogs the men and their equipment from 10 m behind to 10 Mi ahead [Music] even in a sandstorm the work goes on for the navigation beacons must keep well ahead of the ship one day the ship radios that one of the radar beacons many miles behind us has stopped operating it must be adjusted before before the oceanic survey can continue so back over the waves of sand the Skylark goes in search of the tiny Speck that guides the [Music] ship the technician removes the cover makes an adjustment and calls the ship now do you see it [Music] fine at Sea waiting for the beacons It's a lazy day and an old friend comes to [Music] visit the water looks so inviting the geologist decide to go below and look at the bottom and compare the Rocky features with those Exposed on [Music] land an underwater television camera and light is lowered so that those on the ship can see what the divers [Music] see the divers descend into a world of bless where the only sound as their own breathing [Music] they are not quite alone an octopus Dives with them to the seafloor where it glowers ferociously and tries to look as large as possible but the divers are concerned only with geology they are looking for rocks similar to those on Shore they find only sand and a Bat Ray disturbed by these unlikely Intruders turns and flies off into the [Music] Gloom the octopus deciding against Valor also fleases the sand jetting himself to the protective darkness of some weed hung Rock unwittingly he has led the geologist to the Rocks they seek they examine a rocky ledge and chip off fragments so they can see what a fresh rock surface looks [Music] like and then on again but soon it is time to return to the ship up we go okay and thus one more link is added to the chain of knowledge sometimes the sea is calm and sometimes it's not so [Music] calm the weather gets steadily worse but the work goes on until a rising storm forces us to stop operations for the day [Music] [Music] [Music] even the worst weather must end and eventually the ship returns to the calm of table Bay in Cape Town Harbor the splash of the anchor stirs the seabirds the data are taken ashore to be converted into useful Maps now we have a detailed chart of the undersea rocks the yellow patches are soft sediments Sands and gravels the blank areas are Baron Rock the dash lines Mark the rim of the hard sediments the next move is to take samples of the gravels for one must actually recover diamonds from the seafloor to prove that they are there since the samples must be systematic we plan to drill lines of holes at regular intervals Dr David Smith indicates one line where 30 such samples will be taken and processed a new sampling system is required with millions of Rh at stake our Engineers work against the time deadline to construct a ship that can accurately sample the undersea deposits a dredge pump is swung aboard special propellers are made ready a Derek for handling drill pipe and dredging equipment is assembled a console on the bridge makes this ship easy to maneuver for this is Rock Eater of Cape [Music] Town in record time its conversion is completed and it sails for the diamond Coast rock eer is the world's first ship designed specifically for mineral exploration on the run up the coast it is steered automatically by the gyro pilot the captain merely sets the controls and watches the [Music] radar [Music] [Music] Rock eater drops anchor above a gravel bed that was detected by the seismic [Music] survey the captain watching from the bridge gives orders for adjusting the anchor lines and the Chief made on The Vow hears the orders on the intercom and directs the winch [Music] operators the chief geologist aboard checks the ship's position visually by siding on monuments ashore with a pelorus he sings out the angle and it's plotted on the chart [Music] here we will drill for [Music] diamonds the driller lifts the brake and starts the [Music] pumps drill starts [Music] [Music] downward as it goes down water is sucked up the center of the drill pipe it flows along the pipe to the [Music] left when the white stream of water turns brown we will know the bit is drilling into the bottom [Music] there drilling is but the bit grinds its way [Music] downward and now gravel is Flowing along this pipe and onto the screens which sort it according to size the small gravel which contains the diamonds goes through the screen into bins below geologists watch The Bouncing pieces of rock for shist the solid rock which will indicate that the drill has completely penetrated the gravels there that's it retract the [Music] [Music] drill Rock eater drills 30 such holes each day now the overside discharge is white again and already rocker is moving to a new spot to start the next hole below deck the plant operators get ready to process the sorted gravel for diamonds this jigging motion causes the denser Stones including the diamonds to concentrate in the center while a light material flows over the rim periodically the trays are removed and upended on a sorting table so that the concentrates can be examined for [Music] diamonds there's [Music] one diamonds diamonds from under the [Music] sea