WHAT'S UNDER THE OCEAN

[Music] if you if you looked at our Earth far out in space you would see that we live on a watery World oceans cover over 2/3 of the Earth for centuries men have explored the ocean surface but only in the past 100 years or so have we begun to learn about the land under the ocean what is under the ocean to find out some scientists explore small areas of the under ocean Land by diving the tanks they carry are filled with compressed air to allow them to breathe under the water masks protect their eyes and allow them to see underwater these men must be specially trained to use such equipment safely they may take cameras with them to photograph The Depths photographs that allow us to see what they see below the surface of the ocean there is a new world to be explored here is a region swarming with living creatures this gracefully moving animal is a ray here are thousands of bottom dwelling animals in including strangely camouflaged ones like this crab and here is a flatfish our diver has Disturbed on the Sandy Bottom in shallow depths where sunlight can penetrate it is possible for divers to seea nearly as well as on land the animals that live here feed upon smaller animals and upon the plants that grow attached to the many rocks most plants must have sunlight to live but since visible light penetrates the ocean water only for a few hundred fet plant life gradually disappears with depth because of the increasing pressure of the water on a diver's body as he descends few have gone down farther than 200 ft to go deeper specially built ships like this Bosca operated by the United States Navy Electronics laboratory are used it is a kind of underwater balloon that carries scientists to the ocean floor the striped body is a tank to help it move up and down under the tank is a ball shaped Gondola in which the crew rides this is a diagram of the inside of a baos scaff the word bcaf means deep diving ship the biggest part of a baos scaff is a large tank filled with gasoline since gasoline is is lighter than water the Bosca floats the two man crew of scientists ride in this ball-shaped Gondola when they want to go down they allow water to flow into special water tanks then the baos scaff becomes heavy enough to sink the scientists can look through a small window in the gondola and a powerful light enables them to see the bottom in the darkness of the depths the BOS scaff also carries two loads of iron shot when the crew wishes to go up the shot is dumped and the baos scaff Rises to the surface again now let's descend in a bathos scaf to see what's under the ocean the water tank are filled and the ship sinks as it sinks the scientists inside the gondola use a special telephone to keep in touch with ships on the surface through the bcaf window their search light helps them take pictures of what they see on the ocean bottom this picture was taken about 2 miles down it shows that animal life may be found on the ocean bottom even at these great depths the brittle star you see is a relative of the sea star it can exist here even under the weight of tons of water we also see that the deep ocean bottom is covered by a kind of mud called ooze ooze is made of the remains of plants and animals that have sifted down through the water over millions of years by studying this material scientists are able to learn many things about the history of life on Earth but a Bosca can explore only small areas of the ocean floor so scientists also use other ways to learn more about what's under the ocean this is a search ship operated by the scripts institution of oceanography of the University of California oceanography is the study of the ocean scientists on Research ships use many instruments to help them learn about the ocean and its floor this claw-shaped instrument is called an orange peel bucket it snaps shut when it strikes the ocean bottom it can be lowered into the ocean and pulled back with samples of the bottom materials let's see what buckets like this one have brought up this shark tooth is covered with mineral deposits from the deposits scientists know that the shark itself must have lived over a million years ago here is a large piece of Manganese an important mineral someday perhaps men will mine the ocean bottom for minerals like this to learn more about what's under the ocean research ships carry an instrument called an echo Sounder it tells us the shape of the bottom as this diagram shows an echo Sounder sends out sounds which strike the ocean floor and Echo back the time it takes the sound to leave the ship and to return indicates the distance from the ship to the ocean floor the information is recorded as the ship travels over the Water by studying recordings like this one scientists are able to make special maps to show us the shape of the ocean bottom deep beneath the surface here is a map that shows the Atlantic Ocean to have a better understanding of the ocean bottom however let's look at this model a few Islands rise above the water if we drain the water from the model we can see that an island is really the top of a high mountain and we can see that the ocean bottom has other mountains and valleys steep Cliffs and sweeping Plains and in the middle of the Atlantic Ocean B botom there is a long chain of mountains called the mid Ridge this mountain chain divides the ocean floor almost in half the Mid-Atlantic Ridge extends about 10,000 miles from Greenland to Antarctica here is a map of the Pacific Ocean the vast Pacific Basin is almost round this is a model of it in the middle we can see the Hawaiian Islands reaching above the water to see what's under the Pacific we'll drain this model and we discover that the Pacific B with mountains many of them volcanoes like the Hawaiian Islands but most of the Pacific's volcanoes do not reach above the water's surface in the Pacific floor there are many deep trenches among them is the Mariana's Trench perhaps the deepest place on Earth its bottom is almost 7 mil below the ocean surface the Bosca you saw has explored the Mariana's Trench mik these could not have been made without thousands of voyages by oceanographic ships and their scientist Crews Peace by piece over the past 100 years scientists have been exploring the ocean to learn more about our underwater world what's under the ocean a vast Storehouse of plants animals and minerals most of the plant and animal life is found in shallow water where the sun can penetrate and from the deep ocean floor man has brought up some of the minerals and other materials that may be found there today scientists have mapped much of the land under the ocean we know that under the ocean waters there are mountain and valleys steep Cliffs and deep trenches but the area of our Earth covered by oceans still offers science one of its greatest challenges here is a vast World awaiting further exploration a world that man May one day find new and better ways to explore control and use [Music]