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82 THE OCEAN. CHAPTER IX. CURRENTS OF THE SOUTH ATLANTIC AND THE INDIAN OCEAN.—DOUBLE EDDY OF THE PACIFIC OCEAN. The circuit of the waters which occurs to the south of the equator, in the southern basin of the Atlantic, is much less known than that of which the Gulf Stream forms a part; but all that has been observed of it by navigators proves that the movements of the liquid mass are analogous in the two hemispheres. A current of cold water, coming from the Antarctic seas, dashes against the Lagullas Bank to the south of the African continent and divides into two branches, one of which re-enters the Indian Ocean, while the other flows along the western coast of Africa, penetrates into the Gulf of Guinea, and, in consequence of the motion of the earth, bends toward the west in a wide semicircle. To the south of the Cape Verd Islands, the waters coming from the southern seas join those which flow from the.icy sea of the north, and uniting into one river of 500 to 1000 miles wide, move slowly in the direction of South America and the Antilles. The greater mass of water approaches the continent to the north of Cape St. Roque, the advanced promontory of Brazil, and, flowing to the north-west along the coasts of Guiana and Columbia, enters the Caribbean Sea, there to form the Gulf Stream. A less considerable fraction of the equatorial current bends to the south of Cape St. Roque, and follows the Brazilian coast-line to the south-west. But in descending toward latitudes nearer and nearer the southern pole, the warmer current from the equator incessantly gains on the rotatory movement of the earth; consequently, it bends more to the south than to the south-east, and forming a sort of gulf stream in an opposite direction, it strikes the polar current to the east of the Falkland Isles, whose position in the southern hemisphere corresponds to that of Newfoundland in the northern hemisphere. There the warm current, after having deposited drift-wood, taken from the Brazilian coast, on the shores of the Falkland Islands, sinks below the lighter strata of the glacial current; while the latter directs its course to the north-east toward St. Helena, where it joins the great equatorial river. The whole circuit is accomplished in a period which may be estimated at about two or three years.* Dissimilar, and often contradictory, observations recorded by various navigators who have studied the phenomena of the waters in the South Atlantic, seem to put it beyond doubt that the currents of this basin have not the same regularity, of course, as those of the Northern Atlantic. It frequently happens that the water does not flow in the direction indicated on maps, or even tends in an opposite direction to the normal move- * Mittheilungen von Petermann, t. x., 1866.
Title | The ocean, atmosphere, and life |
Creator | Reclus, Elisée |
Publisher | Harper |
Place of Publication | New York |
Date | 1873 |
Language | eng |
Type | Books/Pamphlets |
Title | 00000093 |
Type | Books/Pamphlets |
Transcript | 82 THE OCEAN. CHAPTER IX. CURRENTS OF THE SOUTH ATLANTIC AND THE INDIAN OCEAN.—DOUBLE EDDY OF THE PACIFIC OCEAN. The circuit of the waters which occurs to the south of the equator, in the southern basin of the Atlantic, is much less known than that of which the Gulf Stream forms a part; but all that has been observed of it by navigators proves that the movements of the liquid mass are analogous in the two hemispheres. A current of cold water, coming from the Antarctic seas, dashes against the Lagullas Bank to the south of the African continent and divides into two branches, one of which re-enters the Indian Ocean, while the other flows along the western coast of Africa, penetrates into the Gulf of Guinea, and, in consequence of the motion of the earth, bends toward the west in a wide semicircle. To the south of the Cape Verd Islands, the waters coming from the southern seas join those which flow from the.icy sea of the north, and uniting into one river of 500 to 1000 miles wide, move slowly in the direction of South America and the Antilles. The greater mass of water approaches the continent to the north of Cape St. Roque, the advanced promontory of Brazil, and, flowing to the north-west along the coasts of Guiana and Columbia, enters the Caribbean Sea, there to form the Gulf Stream. A less considerable fraction of the equatorial current bends to the south of Cape St. Roque, and follows the Brazilian coast-line to the south-west. But in descending toward latitudes nearer and nearer the southern pole, the warmer current from the equator incessantly gains on the rotatory movement of the earth; consequently, it bends more to the south than to the south-east, and forming a sort of gulf stream in an opposite direction, it strikes the polar current to the east of the Falkland Isles, whose position in the southern hemisphere corresponds to that of Newfoundland in the northern hemisphere. There the warm current, after having deposited drift-wood, taken from the Brazilian coast, on the shores of the Falkland Islands, sinks below the lighter strata of the glacial current; while the latter directs its course to the north-east toward St. Helena, where it joins the great equatorial river. The whole circuit is accomplished in a period which may be estimated at about two or three years.* Dissimilar, and often contradictory, observations recorded by various navigators who have studied the phenomena of the waters in the South Atlantic, seem to put it beyond doubt that the currents of this basin have not the same regularity, of course, as those of the Northern Atlantic. It frequently happens that the water does not flow in the direction indicated on maps, or even tends in an opposite direction to the normal move- * Mittheilungen von Petermann, t. x., 1866. |
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