The moving waters

Long ago 13 brave men nearly died in the arctic proving what oceanographers now know is a fact: that a broad current of water and ice moves slowly across the top of the world from Siberia to Greenland.

In 1893, led by a young Norwegian, Fridtjof Nansen this group of men sailed from Norway in a small boat, the Pram. More than three years later, the men returned, after a dangerous 1 028-mile voyage through the arctic ice where they could travel only a mile or less each day.

But Nansen proved the existence of a westward-moving current. He found also that this current was caused by the wind, and not by the temperature or salinity differences, as had been thought.

Nansen and another young man, Frederik Johansen had left the ship 226 miles from the North Pole in an unsuccessful attempt to be first to reach the North Pole. But they had to change direction and travel to a deserted island 200 miles north of Siberia. They were rescued by an Englishman named Jackson who with a group of men was returning to England after an unsuccessful attempt to reach the North Pole by land.

On the same day that Nansen arrived in Norway the Fram was moving out of the ice between Spitsbergen and Greenland. Nansen therefore was able to prove that his little ship had been pulled by a current all the way across the frozen Arctic Ocean from Siberia to Spitsbergen.

Currents. – The world's oceans move because of the winds near the equator. These winds blow from the north-east in the northern part of the world, and from the south-east in the southern part of the world. They create huge "across" currents. As the currents quicken, they begin to move as though in a circle. This is because the earth itself turns in a circle, making the northern currents turn to the right and the southern currents turn to the left.

The Gulf Stream is a mixture of many small and large currents. Sometimes these currents change their course or go around and around, or perhaps down deep in the ocean. But the large mass of water that forms the Gulf Stream always moves in the same manner: toward Europe.

Where the Gulf Stream meets the colder waters of the Greenland Current, the Atlantic is covered by low clouds. Most of the Gulf Stream continues down the coast of northern Europe where it becomes the North Atlantic Current. Here it is joined by currents caused by winds near the shore. When it returns to its place of origin, the circle is completed.

In the calm and quiet regions around the equator, winds and currents are weak and sometimes do not exist at all.

In the South Atlantic Ocean the current system moves in a circle, from left to right. As the water hits Brazil, part of the current moves toward the north. Then it turns around and goes down the coast of Africa to complete the circle.

Around the Antarctic Continent, the west wind creates another circle. Here the winds from the South Pole blow the water away from the continent, where it is caught by the westerly winds to form a current. Part of this current joins with others, such as the Brazil Current, as it moves north.

From the deep ocean near Peru and Chile, the winds blow in such a manner that the surface water is moved away and deep, cold waters take their place. This movement brings sea life to the top for fish and birds to feast on. The fish are used as food by man and animals, and to produce certain oils.

Other currents, such as those in the North Расific Ocean and the Indian Ocean, are different and move in a different manner.

Deep Water Movement. – Where does the deep water come from? Where does it go? Oceanographers have found that the great water masses of the world's ocean are produced in two main regions: the icy South Pole and the North Atlantic seas. Here, as surface waters cool and become heavy, they sink toward the bottom. Their action starts currents moving that carry deep, cold water away from the North and South poles toward the equator. This water then slowly sinks down into the deepest part of the world's oceans.

The greatest flow of bottom water starts near the Antarctic: when the surface water begins to freeze. As the water changes to ice, salts are pushed out of the ice, causing the remaining water to become saltier and therefore heavier. It then sinks to the bottom, moving slowly toward the equator.

During the northern winter deep and bottom waters are being produced in the North Atlantic, and they flow toward the south. Salty waters from the Gulf Stream and the Mediterranean add weight to these deep waters as they move south. The North Atlantic deep water becomes caught between the heavier water of the Antarctic bottom and the less salty water that has flowed up from the southern regions. In some sections both the antarctic levels are colder than the North Atlantic level, although usually the deeper the water, the colder it is. Another mixing process occurs in the South Atlantic where some of the antarctic waters combine with the south-flowing deep waters and return to the antarctic.

In the Indian Ocean deep water does not travel south, except for a small amount of salty water pouring in from the Red Sea.

We do not yet know all the facts concerning the deep-water movement of the ocean. In 1955, Dr. Henry Stommel suggested we reexamine some of our accepted theories. He thought it could be possible that the deep water flows south, away from the Pole, not in a wide, slow-moving band, but in quick, narrow streams located along the western sides of the ocean, due to the earth's turning. If Stommel's theory is true, a strong current must exist under the Gulf Stream, bringing cold water toward the equator.

In 1957-1959, oceanographers clearly proved the presence of this strong current under the Gulf Stream. Floats were carried at a rate of five to eight miles a day by the current flowing 6 000 to 10 500 feet beneath the surface. The deep-sea movement of water is being studied by various new methods. One way to find the age of the water (that is to say, when it moved away from the surface) is to measure the oxygen content. "Old" water from the deep ocean has very little oxygen. This is because by the time surface water reached this level, its oxygen has been almost completely used by sea life. The oldest waters are those in the deep part of the ocean near Peru. "Young" waters are found on the surface of the Antarctic and North Atlantic oceans. Here new water is formed each year as the ice melts.

Waves. – The ocean's surface is broken by waves different kinds of waves, from short, little white waves of a windstorm to big waves that beat on sandy beaches with a thunder-like noise. There are also waves we can't see because they move beneath the surface. And there are waves we hope never to see, such as those caused by earthquakes or when undersea volcanoes become active.

Surface waves caused by the wind are the most frequent. Waves are rarely higher than 40 feet, but the highest wave ever recorded was seen during a storm in the Pacific in 1933 and measured more than 100 feet.