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30 THE OCEAN.
Ocean from the 50th degree south to the 50th degree north latitude to be
about 7330 yards. Now, the mean depth of the north basin being very
nearly 2187 fathoms, the depth of the southern basin must be estimated,
according to this calculation, at about 4920 fathoms.* However, these
figures rest on the very contestable and much contested hypothesis that
the tides, instead of forming in a distinct manner in every basin of the
ocean^have a common origin in the great South Polar Sea, and roll toward
the north like one immense wave, in the double valley of the Atlantic, f
As to that part of the Pacific Ocean comprised between Japan and the
coasts of California, it is not by the swiftness of the propagation of the
tides, but by that of the earthquake-waves, that the mean depth may be
approximately estimated. In the terrible earthquake of December 23d,
1854, which partially destroyed several Japanese towns, among others
Yeddo and Simoda, the vibrations of the marine surface traversed an
oceanic space of 6842 miles in twelve hours and a few minutes ; and Prof.
Franklin Bache was able to calculate, in consequence, the swiftness of the
waves and the depth of the Ocean across which they were propagated:
this depth is an average of 2342 fathoms.J Besides, various authentic
soundings taken in the northern basin of the Pacific between California
and the Sandwich Islands confirm the result of this calculation, since they
indicate a depth varying from 1968 to 2570 fathoms. Not far fron#the
coast of California 2700 fathoms of depth have been found.§ Between
the Philippine and the Marianne Islands two other soundings have given
3267 and 3609 fathoms, and even in this last operation the lead has
brought up specimens of the submarine soil, and 117 species of minute
forms of life. Finally, between the Pacific and the Indian Sea, to the
south of the East India Islands, Captain Ringgold found the bottom more
than 8f miles below the surface. Thus one might throw into this abyss
of the sea not only Pelion on Ossa, but Gaourisankar itself, the highest
mountain of the globe; and even if on its peak Mont Blanc were set up,
the summit of this colossus of the continent of Europe would not reach
to the surface of the water.
The Indian Ocean, too, is probably very deep in the greater part of its
extent, but we only know those parts nearest land, and those in hardly
more than an approximate manner. Its gulfs, like those of the Mediterranean and the Atlantic Ocean, have relatively a slight depth of water:
the Persian Gulf, for instance, having a mean depth of only 54, and the
Red Sea of 163 to 273 fathoms. Those parts of the Gulf of Bengal which
are adjacent to the Coromandel Coast and the delta of the Ganges increase only very gradually in depth, except near the northern extremity
of the Gulf, where a prodigious abyss has been discovered, called " the
Great Swatch," which is no less than 2187 fathoms deep, and is bounded
* Sir John Herschel, Physical Geography, p. 72.
t See below, the section entitled The Tides.
% Report of the United States Coast Survey.
§ Sir John Herschel, Physical Geography, p. 39.
| Title | The ocean, atmosphere, and life |
| Creator | Reclus, Elisée |
| Publisher | Harper |
| Place of Publication | New York |
| Date | 1873 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000037 |
| Type | Books/Pamphlets |
| Transcript | 30 THE OCEAN. Ocean from the 50th degree south to the 50th degree north latitude to be about 7330 yards. Now, the mean depth of the north basin being very nearly 2187 fathoms, the depth of the southern basin must be estimated, according to this calculation, at about 4920 fathoms.* However, these figures rest on the very contestable and much contested hypothesis that the tides, instead of forming in a distinct manner in every basin of the ocean^have a common origin in the great South Polar Sea, and roll toward the north like one immense wave, in the double valley of the Atlantic, f As to that part of the Pacific Ocean comprised between Japan and the coasts of California, it is not by the swiftness of the propagation of the tides, but by that of the earthquake-waves, that the mean depth may be approximately estimated. In the terrible earthquake of December 23d, 1854, which partially destroyed several Japanese towns, among others Yeddo and Simoda, the vibrations of the marine surface traversed an oceanic space of 6842 miles in twelve hours and a few minutes ; and Prof. Franklin Bache was able to calculate, in consequence, the swiftness of the waves and the depth of the Ocean across which they were propagated: this depth is an average of 2342 fathoms.J Besides, various authentic soundings taken in the northern basin of the Pacific between California and the Sandwich Islands confirm the result of this calculation, since they indicate a depth varying from 1968 to 2570 fathoms. Not far fron#the coast of California 2700 fathoms of depth have been found.§ Between the Philippine and the Marianne Islands two other soundings have given 3267 and 3609 fathoms, and even in this last operation the lead has brought up specimens of the submarine soil, and 117 species of minute forms of life. Finally, between the Pacific and the Indian Sea, to the south of the East India Islands, Captain Ringgold found the bottom more than 8f miles below the surface. Thus one might throw into this abyss of the sea not only Pelion on Ossa, but Gaourisankar itself, the highest mountain of the globe; and even if on its peak Mont Blanc were set up, the summit of this colossus of the continent of Europe would not reach to the surface of the water. The Indian Ocean, too, is probably very deep in the greater part of its extent, but we only know those parts nearest land, and those in hardly more than an approximate manner. Its gulfs, like those of the Mediterranean and the Atlantic Ocean, have relatively a slight depth of water: the Persian Gulf, for instance, having a mean depth of only 54, and the Red Sea of 163 to 273 fathoms. Those parts of the Gulf of Bengal which are adjacent to the Coromandel Coast and the delta of the Ganges increase only very gradually in depth, except near the northern extremity of the Gulf, where a prodigious abyss has been discovered, called " the Great Swatch," which is no less than 2187 fathoms deep, and is bounded * Sir John Herschel, Physical Geography, p. 72. t See below, the section entitled The Tides. % Report of the United States Coast Survey. § Sir John Herschel, Physical Geography, p. 39. |
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