Fathoms sentence example
The western Mediterranean is cut off by a bank crossing the narrow strait between Sicily and Cape Bon, usually known as the Adventure Bank, on which the depth is nowhere 200 fathoms. The mean depth of the western basin is estimated at 881 fathoms, and the deepest sounding recorded is 2040 fathoms. In the eastern Mediterranean the mean depth is nearly the same as in the western basin.
Many were taken at 10 fathoms and deeper with the line, and all were of exceptionally large size, several measuring 18 in.
The steepest slope observed occurs off the island of Sapienza, near Navarino, where 1720 fathoms has been obtained only 10 miles from land.
The greater part of the bottom of the Atlantic is covered by a deposit of Globigerina ooze, roughly the area between l000 and 3000 fathoms, or about 60% of the whole.
From the surface to 500 fathoms the general form of the isothermals remains the same, except that instead of an equatorial maximum belt there is a focus of maximum temperature off the eastern coast of the United States.Advertisement
Below 500 fathoms the western centres of maximum disappear, and higher temperatures occur in the eastern Atlantic off the Iberian peninsula and north-western Africa down to at least 1000 fathoms; at still greater depths temperature gradually becomes more and more uniform.
The communication between the Atlantic and Arctic basins being cut off, as already described, at a depth of about 300 fathoms, the temperatures in the Norwegian Sea below that level are essentially Arctic, usually below the freezing-point of fresh water, except where the distribution is modified by the surface circulation.
This distribution is most marked at about 300 fathoms, and disappears at soo fathoms, beyond which depth the lines tend to become parallel and to run east and west, the gradient slowly diminishing.
Teredo navalis, it has been found necessary, for depths not exceeding 300 fathoms, to protect the core with a thin layer of brass tape.
The grappling of the cable and raising it to the surface from a depth of 2000 fathoms seldom occupy less than twenty-four hours, and since any extra strain due to the pitching of the vessel must be avoided, it is clear that the state of the sea and weather is the predominating factor in the time necessary for effecting the long series of operations which, in the most favourable circumstances, are required for a repair.Advertisement
As to cost, one transatlantic cable repair cost 75,000; the repair of the Aden-Bombay cable, broken in a depth of 1900 fathoms, was effected with the expenditure of 176 miles of new cable, and after a lapse of 251 days, 103 being spent in actual work, which for the remainder of the time was interrupted by the monsoon; a repair of the Lisbon-Porthcurnow cable, broken in the Bay of Biscay in 2700 fathoms, eleven years after the cable was laid, took 215 days, with an expenditure of 300 miles of cable.
A third curve, from the south-easternmost promontory of the Peloponnese through Cerigo, Crete, Carpathos and Rhodes, marks off the outer deeps of the open Mediterranean from the shallow seas of the archipelago, but the Cretan Sea, in which depths occur over 1000 fathoms, intervenes, north of the line, between it and the Aegean proper.
The greater part of this trough is over 600 fathoms deep. The profusion of islands and their usually bold elevation give beauty and picturesqueness to the sea, but its navigation is difficult and dangerous, notwithstanding the large number of safe and commodious gulfs and bays.
The only part of the sea-bed the configuration of which is at all well known is the zone bordering the coasts where the depth is less than about loo fathoms or 200 metres, i.e.
An elevation of small extent is distinguished as a " dome " when it is more than 100 fathoms from the surface, a " bank " when it is nearer the surface than 100 fathoms but deeper than 6 fathoms, and a " shoal " when it comes within 6 fathoms of the surface and so becomes a serious danger to shipping.Advertisement
By an invention probably due to Humfray Cole and published in 1 578 by William Bourne in his Inventions and Devices, it was proposed to register a ship's speed by means of a "little small close boat," with a wheel, or wheels, and an axle-tree to turn clockwork in the little boat, with dials and pointers indicating fathoms, leagues, scores of leagues and hundreds of leagues.
The depth of the middle portion of the lake has not yet been measured, but must exceed 500 fathoms. It was expected that an underground ridge would be found connecting Olkhon with Svyatoi Nos; but depths exceeding 622 fathoms have been sounded even along that line.
Generally, while there is a relative poverty of zoological groups, there is a great wealth of species within the group. Of gammarids, there are as many as 300 species, and those living at great depths (33 o to 380 fathoms) tend to assume abyssal characters similar to those displayed by the deep-sea fauna of the ocean.
They live in the mud, which they eat, in comparatively shallow waters up to 50 fathoms.
The greatest depth is 1030 fathoms (1227 Russian fathoms) near the centre, there being only one basin.Advertisement
The steepest incline outside loo fathoms is to the southeast of the Crimea and at Amastra; the incline to the greater depths is also steep off the Caucasus and between Trebizond and Batum.
The existence of sulphuretted hydrogen in great quantities below loo fathoms, the extensive chemical precipitation of calcium carbonate, the stagnant nature of its deep waters, and the absence of deep-sea life are conditions which make it impossible to discuss it along with the physical and biological conditions of the Mediterranean proper.
The depths of the Black Sea are lifeless, higher organic life not being known to exist below loo fathoms. Fossiliferous remains of Dreissena, Cardium and other molluscs have, however, been dredged up, which help to show that conditions formerly existed in the Black Sea similar to those that exist at the present day in the Caspian Sea.
During summer the surface salinity of the Black Sea is from 1.70 to 2'00% down to 50 fathoms, whereas in the greater depths it attains a salinity of 2.25%.
The temperature is rather remarkable, there being an intermediate cold layer between 25 and 50 fathoms. This is due to the sinking of the cold surface water (which in winter reaches freezing-point) on to the top of the denser more saline water of the greater depths.Advertisement
The Sea of Azov is exceedingly shallow, being only about 6 fathoms in its deepest part, and it is largely influenced by the river Don.
A submarine ridge, about 300 fathoms deep at its deepest, unites Greenland with Iceland (across Denmark Strait), the Faeroes and Scotland.
These fjords are very deep; the greatest depth found by Ryder in Scoresby Sound was 300 fathoms, but there are certainly still greater depths; like the Norwegian fjords they have, however, probably all of them, a threshold or sill, with shallow water, near their mouths.
Finally, the plankton (and again the vegetable forms in particular) are practically restricted to the upper hundred fathoms or so of the sea.
Daly estimates that the maximum lowering of ocean level due to this cause would only amount to 36 fathoms, but even that would be the cause of very marked geological effects.
William Gilpin, who is so admirable in all that relates to landscapes, and usually so correct, standing at the head of Loch Fyne, in Scotland, which he describes as "a bay of salt water, sixty or seventy fathoms deep, four miles in breadth," and about fifty miles long, surrounded by mountains, observes, "If we could have seen it immediately after the diluvian crash, or whatever convulsion of nature occasioned it, before the waters gushed in, what a horrid chasm must it have appeared!
Owing to the increased friction produced by a rotator making approximately 900 revolutions per mile, towed at the end of a line varying from 40 fathoms for a 12 -knot FIG.
Finally, Glandiceps abyssicola (Spengelidae) was dredged during the "Challenger" expedition in the Atlantic Ocean off the coast of Africa at a depth of 2500 fathoms.
The natural harbour, which, with a depth diminishing from 70 to 30 fathoms, strikes in from the northwest so as to cut the island into two fairly equal portions, with an isthmus not more than 14 m.
Below 150 fathoms they are rare, but a few such as Terebratulina wyvillei are found down to 2000 fathoms. Lingula is essentially a very shallow water form.
It is a widelydistributed species, being found throughout the northern and temperate seas of Europe, Asia and America, extending as far south as Gibraltar, but not entering the Mediterranean, and inhabits water from 25 to 50 fathoms deep, where it always feeds close to the bottom.
The levels are supposed to be I o fathoms (60 ft.) apart.
The extreme depth of the strait approaches 50 fathoms, and it contains two small islands known as the Diomede Islands.
The southern coast in particular is deeply indented; and there two bold peninsulas, extending for several miles into the sea, form two capacious natural harbours, namely, Deep Water Bay, with the village of Stanley to the east, and Tytam Bay, which has a safe, well-protected entrance showing a depth of 10 to 16 fathoms. An in-shore island on the west coast, called Aberdeen, or Taplishan, affords protection to the Shekpywan or Aberdeen harbour, an inlet provided with a granite graving dock, the caisson gate of which is 60 ft.
There is good anchorage throughout the entire channel separating the island from the mainland, except in the Ly-ee-mun Pass, where the water is deep; the best anchorage is in Hong-Kong roads, in front of Victoria, where, over good holding ground, the depth is 5 to 9 fathoms. The inner anchorage of Victoria Bay, about a m.
There the bottom slopes very abruptly, descending precipitously at a point not far from the north-east coast of the main island, where soundings have shown 4655 fathoms. This, the deepest sea-bed in the world, is called the Tuscarora Deep, after the name of the United States man-of-war which made the survey.
On the other hand, the average depth of the Japan Sea is only 1200 fathoms, and its maximum depth is 3200.
These last have not been found anywhere except at the entrance of the Bay of Tokyo at a depth of some 200 fathoms.
Dr Livingstone obtained a depth of 326 fathoms opposite Mount Kabogo, south of Ujiji.
Mr Hore often failed to find bottom with a line of 168 fathoms. The French explorer, Victor Giraud, reported 647 metres (about 350 fathoms) off Mrumbi on the west coast, and Moore depths of 200 fathoms and upwards near the south end.
It has a depth of 6 to io fathoms, with a good bottom, and large ships can anchor at a cable's length from the shore.
During Nansen's expedition on the " Fram " in 1894-1895, Scott Hansen made observations with a Sterneck's half-seconds pendulum on the ice where the sea was more than 1600 fathoms deep and found only an insignificant deviation from the number of swings corresponding to a normal ellipsoid.
This epoch-making great discoverers of the modern period were only familiar with expedition lasted from Christmas 1872 to the end of May 1876, the hand-lead, and the lines in use did not exceed 200 fathoms and gave the first wide and general view of the physical and in length.
He spliced together all the sounding-lines on board, rightly said that since the days of Columbus and Magellan no and with a weight of 1501b attached he found bottom in 683 such revelation regarding the surface of our planet had been fathoms and secured a sample of fine soft blue mud.
Polar explorers making sections across the great expanses of water with everfrequently repeated those experiments in deep-sea soundings, increasing accuracy, and in that work the government surveying both William Scoresby and Sir John Ross obtaining notable ships have also been engaged, vast stretches of the Indian and results, though not reaching depths of more than 1200 fathoms. Pacific Oceans having been opened up to knowledge by H.M.SS.
All attempts to dispense with a lead and line and to measure the depth by determining the pressure at the bottom have hitherto failed when applied to depths greater than 200 fathoms; a new hydraulic manometer has been tried on board the German surveying ship " Planet."
It is improbable, however, that the smooth and slender wire is much influenced by currents, and the best deep-sea soundings may be taken as accurate to within 5 fathoms.
Kriimmel has calculated the mean depth to be 2010 fathoms (12,060 ft.), while the mean elevation of the surface of the continents above sea-level is only 2300 ft.
The continental shelf is the gentle slope which extends from the edge of the land to a depth usually about loo, though in some cases as much as 300 fathoms, and is there demarcated by an abrupt increase in the steepness of the slope to ocean depths.
Amongst these are the dome, an isolated elevation rising steeply but not coming within too fathoms of the surface; the bank, an elevation coming nearer the surface than too fathoms, but not so near as 6 fathoms; and finally the shoal or reef, which comes within 6 fathoms of the surface, and so may constitute a danger to shipping.
In particular Sir John Murray considers that only deeps exceeding 3000 fathoms in depth should be named, and in his charts he has named these deeps after persons whether the individuals thus honoured had themselves discovered or explored the deeps in question or not.
Such valleys are very clearly indicated in the belts of the western Baltic by furrows a thousand yards wide and twenty to thirty fathoms deeper than the neighbouring sea-bed.
The North African Basin has several deeps with more than 3300 fathoms to the northwest and the south-west of the Cape Verde Islands, but the South African Basin is less deep. In the South Atlantic there is no connexion between the Central Rise and the Antarctic Shelf, for the Indo-Atlantic Antarctic Basin stretches from near the South Sandwich Islands towards Kerguelen with depths exceeding 2500 fathoms and reaching in places 3100.
Bruce, in the " Scotia," showed in 1904 that the real depth at that point is only 2660 fathoms.
This rise is separated from the Crozet Rise by a depression extending to 2675 fathoms, through which the Kerguelen Trough (which lies north of Kerguelen) is brought into free communication with the Indo-Atlantic Antarctic Basin.
The Australian Shelf rises steeply as a rule from depths, of 2500 to 3000 fathoms. A broad depression with depths of from 3300 to 3500 fathoms lies to the east of the Cocos Islands and extends into the angle between the Malay Archipelago and Australia.
Half of this basin lies deeper than 2750 fathoms, and the greater part of it belongs to the northern hemisphere.
From the floor of this vast and profound depression numerous isolated volcanic cones rise with abrupt slopes, and even between the islands of the Hawaiian group there are depths of more than 2000 fathoms. The Society Islands and Tahiti crown a rise coming within 150o fathoms of the surface, two similar rises form the foundation of the Paumotu group where Agassiz found soundings of.
This great trench is continued along the Luchu.Islands where the cable-steamer " Stephan " sounded in 4080 fathoms, and through the Bonin Trench (with a maximum of 3595 fathoms) to the famous Marianne Trench in which the U.S.S.
The northern part of the Marianne Trench leads to a wave-like configuration of the ocean floor, the depth to the east of Saipan being over 4300 fathoms, followed by a rise to 1089 fathoms and then a descent to 3167 fathoms.
The trenches of Yap (4122 fathoms) and Palau (Pelew) (4450 fathoms) are not immediately connected with that of Marianne.
To the east of the Philippines a sounding of 3490 fathoms is found close to the Strait of St Bernardino and north-east of Talaut.
There are no depths, however, much exceeding 2500 fathoms amongst these depressions.
The ridge across Denmark Strait west of Iceland nowhere exceeds 300 fathoms in depth, so that the deeper water of the North Polar Basin is effectively separated from that of the Atlantic. A third small basin occupies Baffin Bay and contains a maximum depth of 1050 fathoms. Depths of from loo to 300 fathoms are not uncommon amongst the channels of the Arctic Archipelago north of North America, and Bering Strait, through which the surface water of the Arctic Sea meets that of the Pacific, is only 28 fathoms deep.
The Central American Sea communicates with the Atlantic through the channels between the Antilles, none of which is quite 1000 fathoms deep, and it sinks to a depth of 2843 fathoms in the Caribbean Basin, 3428 fathoms in the Cayman Trench and 2080 fathoms in the Gulf of Mexico.
The China Sea on the north has a maximum depth of 2715 fathoms off the Philippines, the Sulu Basin reaches 2550 fathoms, and the Celebes Basin 2795 fathoms. Some of the channels between the islands are of very great depth, Macassar Strait exceeding 1000 fathoms, the Molucca Passage exceeding 2000 fathoms, and the Halmahera Trough sinking as deep as 2575 fathoms. The deepest of all is the Banda Basin, a large area of which lies below 2500 fathoms and reaches 3557 fathomsin the Kei Trench.
A depth of 2789 fathoms also occurs north of Flores.
The Mediterranean Sea, the best-known member of the intercontinental class, is separated from the Atlantic Ocean by a ridge running from Cape Spartel to Cape Trafalgar on which the greatest depth is only 175 fathoms. The depth increases so rapidly towards the east that soundings exceeding 500 fathoms occur off Gibraltar.
The Adriatic Sea though very shallow in the north deepens southward to about 9 00 fathoms, and the Aegean Sea has a maximum depth of 1230 fathoms north of Crete.
The Persian Gulf nowhere exceeds 50 fathoms, the southern part of Hudson .Bay does not exceed Too fathoms except at one spot, though in the less-known fjords of the northern part depths up to 200 fathoms have been reported.
In the North Sea the depth of ioo fathoms is only exceeded to any extent in the Norwegian gully, which has a maximum depth of 383 fathoms in the Skagerrack.
In the Bering Sea the trough north of Buldir in the Aleutian Islands sinks to 2237 fathoms, and in the Sea of Okhotsk, north-west of the Kuriles, to 1859 fathoms. Similar conditions prevail in the East China Sea and the Andaman Sea.
The Sea of Japan has a wide shelf only in the north, the central part forms a broad basin with depths of 1650 fathoms. The Laurentian Sea (Gulf of St Lawrence) has a narrow branching gully running between wide shelves, in which a depth of 312 fathoms is found south of Anticosti.
In depths down to ico fathoms the old-fashioned hand-lead, hollow below and " armed " with tallow, suffices to bring up a sample large enough to be recognizable.
Captain Phipps in 1773 secured samples of soft blue clay in this manner from a depth of 683 fathoms, but as a rule when sounding in great depths the sample is washed off the tallow before it can be brought on board.
It is particularly in evidence round the whole of the Antarctic Shelf, where it occurs down to depths of 2500 fathoms. It is the chief deposit, according to Nansen, of the North Polar Basin and, according to Schmelck and Bdggild, of the Norwegian Sea also, where it is largely mixed with the shells of the bottom-living foraminifer Biloculina.
The formation of the blue mud is largely aided by the putrefaction of organic matter, and as a result the water deeper than 120 fathoms is extraordinarily deficient in dissolved oxygen and abounds in sulphuretted hydrogen, the formation of which is brought about by a special bacterium, the only form of life found at depths greater than 120 fathoms in the Black Sea.
It is a remarkable geographical fact that on the rises and in the basins of moderate depth of the open ocean the organic oozes preponderate, but in the abysmal depressions below 2500 or 3000 fathoms, whether these lie in the middle or near the edges of the great ocean spaces, there is found only the red clay, with a minimum of calcium carbonate, though sometimes with a considerable admixture of the siliceous remains of radiolarians.
Out of 118 samples of globigerina ooze obtained by the " Challenger " expedition 84 came from depths of 1500 to 2500 fathoms, 13 from depths of loon to 150o and only 16 from Scot.
These shells do not retain their individuality at depths greater than 1400 or 1500 fathoms, and in fact pteropod ooze is only found in small patches on the ridges near the Azores, Antilles, Canaries, Sokotra, Nicobar, Fiji and the Paumotu islands, and on the central rise of the South Atlantic between Ascension and Tristan d'Acunha.
Red clay was discovered and named by Sir Wyville Thomson on the " Challenger " in 1873 when sounding in depths of 2700 fathoms on the way from the Canary Islands to St Thomas.
Red clay is the deposit peculiar to the abysmal area; 70 carefully investigated samples collected by the " Challenger " came from an average depth of 2730 fathoms, 97 specimens collected by the " Tuscarora " came from an average depth of 2860 fathoms, and 26 samples obtained by the " Albatross " in the Central Pacific came from an average depth of 2620 fathoms. Red clay has not yet been found in depths less than 2200 fathoms. The main ingredient of the deposit is a stiff clay which is plastic when fresh, but dries to a stony hardness.
A very interesting feature is the small proportion of calcium carbonate, the amount present being usually less as the depth is greater; red clay from depths exceeding 3000 fathoms does not contain so much as 1% of calcareous matter.
In the North Sea north of the Dogger Bank, for instance, the disk is visible in calm weather to a depth of from io to 16 fathoms, but in rough weather only to 62 fathoms. Knipovitch occasionally observed great transparency in the cold waters of the Murman Sea, where he could see the disk in as much as 25 fathoms, and a similar phenomenon has often been reported from Icelandic waters.
Luksch found the disk visible as a rule to from 22 to 27 fathoms, and off the Syrian coast even to 33 fathoms. In the open Atlantic there are `great differences in transparency; Kriimmel observed a 6 ft.
Mill has shown that in the North Sea off the Firth of Forth the average depth of visibility of a disk in the winter half-year was 4; fathoms and in the summer half-year 62 fathoms, and, although the greater frequency of rough weather in winter might tend to obscure the effect, individual observations made it plain that the angle of the sun was the main factor in increasing the depth to which the disk remained visible.
Fol and Sarasin detected the last traces of sunlight in the western Mediterranean at a depth of 254 to 260 fathoms, and Luksch in the eastern Mediterranean at 328 fathoms and in the Red Sea at 273 fathoms. The chief cause of the different depths to which light penetrates in sea-water is the varying turbidity due to the presence of mineral particles in suspension or to plankton.
Buchanan found a mean of 20 experiments made by piezometers sunk in great depths on board the " Challenger " give a coefficient of compressibility K=491 X 107; but six of these experiments made at depths of from 2740 to 3125 fathoms gave K=480Xio 7.
In other words, water which has a specific gravity of 1 0280 at the surface would at the same temperature have a specific gravity of 1 0450 at 2000 and I 0540 at 3000 fathoms. If the whole mass of water in the ocean were relieved from pressure its volume would expand from 319 million cub.
When these processes continue for a long time in deep water shut off from free circulation so that it does not become aerated by contact with the atmosphere the water becomes unfit to support the life of fishes, and when the accumulation of putrefying organic matter gives rise to sulphuretted hydrogen as in the Black Sea below 125 fathoms, life, other than bacterial, is impossible.
The water from the greatest depths of the Black Sea, I160 fathoms, contains 6 cc. of sulphuretted hydrogen per litre.
Dittmar's analysis of the " Challenger " samples indicated an excess of oxygen in the surface water of high southern latitudes and a deficiency at depths below 50 fathoms.
The amount of carbonic acid in solution may also be increased by submarine exhalations in regions of volcanic disturbance, but it must be remembered that the critical pressure for this gas is 73 atmospheres, which is reached at a depth of 400 fathoms, so that carbonic acid produced at the bottom of the ocean must be in liquid form.
The use of a sliding weight is not recommended in depths much exceeding 200 fathoms on account of the time required and the risk of the line sagging at a low angle and so stopping the weight.
In deep water the closing mechanism is usually actuated by a screw propeller which begins to work when the line is being hauled in and can be set so as to close the waterbottle in a very few fathoms. A small but heavy water-bottle has been devised by Martin Knudsen, provided with a pressure gauge or bathometer, by which samples may be collected from any moderate depth down to about roc fathoms, on board a vessel going at full speed.
Buchanan pointed out in 1876, that the great contrasts in surface salinity between the tropical maxima and the equatorial minima give place at the moderate depth of 200 fathoms to a practically uniform salinity in all parts of the ocean.
In the North Atlantic a strong submarine current flowing outward from the Mediterranean leaves the Strait of Gibraltar with a salinity of 38 per mille, and can be traced as far as Madeira and the Bay of Biscay in depths of from 600 to 2800 fathoms, still with a salinity of 35.6 per mille, whereas off the Azores at equal depths the salinity is from 0.5 to 0.7 per mille less.
In the tropical and subtropical belts of the Atlantic and Indian Oceans south of the equator the salinity diminishes rapidly from the surface downwards, and at 500 fathoms reaches a minimum of 34.3 or 34.4 p e r mille; after that it increases again to 800 fathoms, where it is almost 34.7 or 34.8, and this salinity holds good to the bottom, even to the greatest depths, as was first shown by the " Gauss " and afterwards by the " Planet " between Durban and Ceylon.
Our knowledge of the Pacific in this respect is still very imperfect, but it appears to be less salt than the other oceans at depths below 800 fathoms, as on the surface, the salinity at considerable depths being 34.6 to 34.7 in the Western part of the ocean, and about 34.4 to 34.5 in the eastern, so that, although the data are by no means satisfactory, it is impossible to assign a mass-salinity of more than 34.7 per mille for the whole body of Pacific water.
The observations of Aime in 1845 and of Semmola in the Gulf of Naples in 1881 show that the surface water in winter cools until the whole mass of water from the surface to the bottom, in 1600 fathoms or more, assumes the same temperature.
Curve B shows the typical distribution of temperature in an enclosed sea, in this case the Sulu Basin of the Malay Sea, where from the level of the barrier to the bottom the temperature remains uniform or homothermic. Curve C shows a typical summer condition in the polar seas, where layers of sea-water at different temperatures are superimposed, the arrangement from the surface to 200 fathoms is termed FIG.
The nature of the change of temperature with depth below 2500 fathoms is entirely dependent on the position of the sub-oceanic elevations, for the rises and ridges act as true submarine watersheds.
As the Arctic Basin is shut off from the North Atlantic by ridges rising to within 300 fathoms of the surface and from the Pacific by the shallow shelf of the Bering Sea, and as the ice-laden East Greenland and Labrador currents consist of fresh surface water which cannot appreciably influence the underlying mass, the Arctic region has no practical effect upon the bottom temperature of the three great oceans, which is entirely dominated by the influence of the Antarctic. The existence of deep-lying and extensive rises or ridges in high southern latitudes has been indicated by the deep-sea temperature observations of Antarctic expeditions.
Thus in the Central American Sea below 93 o fathoms, the depth on the bar, no water is found at a temperature lower than that prevailing in the open ocean at that depth, viz.
Vertical movements are also produced by difference of temperature in the water, but these can only be feeble, as below 'coo fathoms the temperature differences between tropical and polar waters are very small.
The existence of a layer of water of low salinity at a depth of 500 fathoms in the tropical oceans of the southern hemisphere is to be referred to this action of the melting ice of the Antarctic regions.
The Kerguelen plateau rises in many parts to within 1500 fathoms of the surface of the sea.
The anchorage is fairly protected from the sea, but the depth of water is only 3 to 4 fathoms. The channel between the island on Diu and the mainland is navigable only by fishing boats and small craft.
They bought practically all of what is now Essex county from the Indians for "fifty double hands of powder, one hundred bars of lead, twenty axes, twenty coats, ten guns, twenty pistols, ten kettles, ten swords, four blankets, four barrels of beer, ten pairs of breeches, fifty knives, twenty horses, eighteen hundred and fifty fathoms of wampum, six ankers of liquor (or something equivalent), and three troopers' coats."
The town is traversed by canals, and the harbour, which has from 4 to 8 fathoms water, is landlocked by several islands.
Practically the whole of the north-east Pacific is therefore more than 2000 fathoms deep, and the south-east has two roughly triangular spaces, including the greater part of the area, between 2000 and 3000 fathoms. Notwithstanding this great average depth, the " deeps " or areas over 3000 fathoms are small in number and extent.
Depths of less than 2000 fathoms occur continuously on a bank extending from south-eastern Asia, on which stands the Malay Archipelago.
The most considerable areas over 3000 fathoms are the Aldrich deep, an irregular triangle nearly as large as Australia, situated to the east of New Zealand, in which a sounding of 5155 fathoms was obtained by H.M.S.
A long strip within the Tuscarora deep forms the largest continuous area with a depth greater than 4000 fathoms. All the rest of the western Pacific is a region of quite irregular contour.
The average depth varies from 1500 to 2500 fathoms, and from this level innumerable volcanic ridges and peaks rise almost or quite to the surface, their summits for the most part occupied by atolls and reefs of coral formation, while interspersed with these are depressions, mostly of small area, among which the deepest soundings recorded have been obtained.
The Golfo Dulce has an average depth of too fathoms and contains no islands.
The Tempisque enters the Pacific at the head of the Gulf of Nicoya, and tends to silt up that already shallow inlet (5-10 fathoms) with its alluvial deposits.
It was therefore equal to 79,200 in., and divided decimally into 10 furlongs 100 chains, or 1000 fathoms. For the existence of this fathom (half the Belgic pertica) we have the proof of its half, or yard, needing to be suppressed by statute (9) in 1439, as "the yard and full hand," or about 40 in., -- evidently the yard of the most usual old English foot of 13.22, which would be 39.66.
The depth ranges from 18 to 19 fathoms at the entrance to 42 fathoms along the inner shore line.
The depth of water at the main entrance is 41 to 5 fathoms and in the western bay 3 to 4 fathoms. For lack of docks and quayage, large vessels lie off Steamer Point and all cargo is handled by means of lighters, the labour being either Somali or Arab.
There are no good harbours, and the only anchorage for large vessels is Tai-chung, or Yung-su, at the east end, with 9 to 13 fathoms of water.
Some are littoral, living between tide-marks; others are found at very various depths, up to 2800 fathoms. A few species have invaded the fresh waters, while the pulmonate and terrestrial Gastropods are distributed over the whole surface of the land in all latitudes and to a height of 15,000 ft.
The harbour is eleven to thirteen fathoms deep at the entrance (indicated by a lighthouse), decreasing to five fathoms near the shore.
There is anchorage for steamers in 5 to 6 fathoms. Vessels were loaded and discharged by lighters from the beach.
The north part of the sea is very shallow, and between the southern promontory of Istria and Rimini the depth rarely exceeds 25 fathoms. Between Sebenico and Ortona a well-marked depression occurs, a considerable area of which exceeds Ioo fathoms in depth.
The deepest part of the sea lies east of Monte Gargano, south of Ragusa, and west of Durazzo, where a large basin gives depths of 500 fathoms and upwards, and a small area in the south of this basin falls below 800.
The mean depth of the sea is estimated at 133 fathoms. The bora (north-east wind), and the prevalence of sudden squalls from this quarter or the south-east, are dangers to navigation in winter.
Neomenia and its allies are marine animals living at depths of 15 to Boo fathoms on soft muddy ground; they are found crawling on corals and hydrozoa, on which they feed.
This is the shallowest part, barely reaching a depth of 20 fathoms. It is being gradually 1 By the triangulation of 1840 its level was found to be 84 ft.
It is separated from (3), the southern and deepest section of the Caspian, by a submarine ridge (30 to 150 fathoms of water), which links the main range of the Caucasus on the west with the Kopet-dagh in the Transcaspian region on the east.
The depth in this section ranges from 300 to 500 fathoms, with a maximum of 602 fathoms.
The Knipovich expedition in 1004 found no traces of organic life below the depth of 220 fathoms except micro-organisms and a single Oligochaete; but above that level there exist abundant evidences of rich pelagic life, more particularly from the surface down to a depth of 80 fathoms.
Kinsale, with the neighbouring villages of Scilly and Cove, is much frequented by summer visitors, and is the headquarters of the South of Ireland Fishing Company, with a fishery pier and a commodious harbour with 6 to 8 fathoms of water; but the general trade is of little importance owing to the proximity of Queenstown and Cork.
The channel between Cape Bon in Tunis and the south-west of Sicily (a distance of 80 m.) is, on the whole, shallower than the Straits of Messina, being for the most part under 100 fathoms in depth, and exceeding 200 fathoms only for a very short interval, while the Straits of Messina, have almost everywhere a depth exceeding 150 fathoms. The geological structure in the neighbourhood of this strait shows that the island must originally have been formed by a rupture between it and the mainland, but that this rupture must have taken place at a period long antecedent to the advent of man, so that the name Rhegium cannot be based even on the tradition of any such catastrophe.
It is the most numerous genus, and consists for the most part of shallow-water (less than 50 fathoms) tropical and subtropical forms. They often live in tubular burrowings in coral-rock.
At more than one point a depth exceeding 1000 fathoms has been ascertained.
Its port has a depth of 4 to 6 fathoms, and a roadstead 32 m.
Pearling Industry.-The pearling grounds of Bahrein are in over six fathoms of water, mostly beyond the three-mile limit.
The coral banks which surround Sokotra and The Brothers are united and are not more than 30 fathoms below sea-level; a valley some loo fathoms deep divides them from the bank around Abd-el-Kuri, while between Abd-el-Kuri and Cape Guardafui are depths of over 500 fathoms.
The depth of the sea around the shore rarely exceeds a maximum depth of 1 to 3 fathoms, and the coast as a whole offers few accessible ports.
At a great distance from its mouth it has still a depth of three fathoms, and in all its physical features it is comparable to the Kapuas and Barito.
The depth in the main entrance varies from 10 to 17 fathoms, and vessels drawing 20 ft.
They burrow in the sands of every shore; they throng the weeds between tide-marks; they ascend all streams; they are found in deep wells, in caverns, in lakes; in Arctic waters they swarm in numbers beyond computation; they find lodgings on crabs, on turtles, on weed-grown buoys; they descend into depths of the ocean down to hundreds or thousands of fathoms; they are found in mountain streams as far above sea-level as some of their congeners live below it.
To the north-west of the volcanic island of Zebayir the depth is less than 500 fathoms; the bottom of the channel rises to the ioofathom line at Hanish Island (also volcanic), then shoals to 45 fathoms, and sinks again in about the latitude of Mokha in a narrow channel which curves westward round the island of Perim (depth 170 fathoms), to lose itself in the Indian Ocean.
From the observations of salinity it is inferred that a surface current flows inwards to the Red Sea in the eastern channel of the Strait of Bab el-Mandeb, while a current of very salt water flows outward to the Indian Ocean, through the western channel, at a depth of 50 to loo fathoms from the surface.
Natural beds of oysters occur on stony and shelly bottoms at depths varying from 3 to 20 fathoms. In nature the beds are liable to variations, and, although Huxley was somewhat sceptical on this point, it seems that they are easily brought into an unproductive condition by over-dredging.
To be but a hand's-breadth below the surface of the sea ensures drowning as infallibly as to be five hundred fathoms deep. Now the wise man is drawn as perfect.
Except along the centre of the Irish Sea, at one point off the Tweed and one between Devon and Normandy, the depth of water between England and the nearest land nowhere exceeds 50 fathoms.
It affords good anchorage, with nearly 7 fathoms of water, and is well sheltered, except from winds which blow from points between south-east and south-west.
In the latter winds Sorrento should be especially avoided, as no safe anchorage can be found there at less than 15 fathoms, and the same remark applies to Capri with winds from S.W.
The Seychelles lie, with two exceptions, towards the centre of a large submarine bank and are all within the so fathoms line.
The depth of the bay ranges from 42 to 19 fathoms. The town stands at the foot of the Sierra Nevada de Santa Marta, which restricts the area of cultivatable land in its immediate vicinity, and the enclosing high lands make the climate hot and somewhat dangerous for foreigners.
Alcyonium digitatum, a pink digitate form popularly known as" dead.men's fingers,"is common in 10 -20 fathoms of water off the English coasts.
A ridge, less than 2000 fathoms from the surface, extends south-eastwards from the Cape.
Immediately to the north of Wharton deep is the smaller "Maclear deep," and the long narrow "Jeffreys deep" off the south of Australia completes the list of depressions below 3000 fathoms in the Indian Ocean.
Off the African coasts there are large deposits of Glauconitic sands and muds at depths down to moo fathoms, and on banks where coral formation occurs there are large deposits of coral muds and sands.
Between the depths of 100 and moo fathoms temperature is high in the north-west, and in the south centre and south-west, and low in the north-east, the type of distribution remaining substantially the same.
The strait separating it from Celebes is more than ioo fathoms deep and, running in a strong current, is dangerous for native ships to navigate.
Here the tidal phenomenon called the bore, or Pororoca, occurs, where the soundings are not over 4 fathoms. It commences with a roar, constantly increasing, and advances at the rate of from 10 to 5 m.
Along the Swedish coast a deep channel runs northward from outside the island of Oland; this is entirely cut off to the south and east by a bank which sweeps eastward and northward from near Karlskrona, and on which the island of Gotland stands, but it communicates at its northern end with the Gotland deep, and near the junction opposite Landsort is the deepest hole in the Baltic (420 metres = 2 3 o fathoms).
In the great basins and hollows from Rugen to the Gulfs of Bothnia and Finland the upper layers of water, from 30 to 70 metres (16 to 38 fathoms) in thickness, have almost the same salinity throughout.
Geographically the cluster certainly belongs to the mainland, from which it is separated by Rosario Strait, generally much under 50 fathoms in depth, while Haro Strait, separating it from Vancouver Island, has depths ranging from ioo to 190 fathoms. In 1873 the islands, formerly considered part of Whatcom county, Washington, were made the separate county of San Juan.
The anchorage, about a mile from the town, in 4 to 6 fathoms, is nothing but an open roadstead.
This cone rises from a depth of Boo fathoms below the sea.
Off the peninsula of Mullet (county Mayo) there are ioo fathoms of water within 25 m.
The depth between the islands is in some places over 1000 fathoms.
As a rule the lakes which occupy portions of the great rift-valleys have steep sides and are very deep. This is the case with the two largest of the type, Tanganyika and Nyasa, the latter of which has depths of 430 fathoms. Others, however, are shallow, and hardly reach the steep sides of the valleys in the dry season.
Lakes of the broad type are of moderate depth, the deepest sounding in [[Victoria (disambiguation)|Victoria ]] being under 50 fathoms. Apart from the seasonal variations of level, most of the lakes show periodic fluctuations, while a progressive desiccation of the whole region is said to be traceable, tending to the ultimate disappearance of the lakes.
Whitebait are caught on the flood-tide from boats moored in from 3 to 5 fathoms of water.
Second only to the compass in its value to the sailor is Thomson's sounding apparatus, whereby soundings can be taken in 100 fathoms by a ship steaming at 16 knots; and by the employment of piano-wire of a breaking strength of 140 tons per square inch and an iron sinker weighing only 34 lb, with a selfregistering pressure gauge, soundings can be rapidly taken in deep ocean.
Its greatest depth is about 700 fathoms, the deepest parts (over Soo fathoms) occurring in three depressions in the northern portion - one close under the European shore to the south of Rodosto, another near the centre of the sea, and a third at the mouth of the Gulf of Ismid.
The engine shaft will sink in the ground at 130 fathoms.
The Western Shaft was sunk to a depth of forty fathoms.
These pumps are capable of supplying ample air to two divers simultaneously, at the depth of twelve fathoms.
It was how many fathoms below the surface?
There were fathoms of water, which meant the masts were not visible.
The shipwreck was many fathoms from the surface.
About 83 fathoms further west the Bog shaft is drained by the same adit " .
I succeeded in getting the conch so near that I could only give her about 30 fathoms of chain.
Each drift net would be up to 120 fathoms long, up to 12 nets would be joined together to create the drift.
This vein has an upthrow to the north of 14 fathoms.
Rhabdopleura is no doubt of world-wide distribution, since it has been recorded in various localities from Greenland to South Australia, usually in water of not less than forty fathoms. Cephalodiscus, which for many years was known solely as the result of a single dredging by the " Challenger " from 2 4 5 fathoms in the Straits of Magellan, has recently been found in entirely different parts of the world, as for instance between Japan and Korea at ioo fathoms, at about half that depth off the south-east coast of Celebes, and between tide-marks on the coast of Borneo.
Over g p this ridge the average depth is about 1700 fathoms.
In these troughs the depth is seldom much less than 3000 fathoms, and this is exceeded in a series of patches to which Murray has given the name of " Deeps."
In the case of the Gulf Stream, which is not much impeded by the land, this descending motion is relatively slight, being perhaps largely due to the greater specific gravity of the water; it ceases to be perceptible beyond about 500 fathoms. On the European-African side the descending movement is more marked, partly because the coast-line is much more irregular and the northward current is deflected against it by the earth's rotation, and partly because of the outflow of salt water from the Mediterranean; here the movement is traceable to at least 1000 fathoms. The northward movement of water across the Norwegian Sea extends down from the surface to the IcelandShetland ridge, where it is sharply cut off; the lower levels of the Norwegian Sea are filled with ice-cold Arctic water, close down to the ridge.
He showed that an imaginary spheroidal shell, concentric with the earth and cutting the slope between the elevated and depressed areas at the contour-line of 1700 fathoms, would not only leave above it a volume of the crust equal to the volume of the hollow left below it, but would also divide the surface of the earth so that the area of the elevated region was equal to that of the depressed region.6 A similar observation was made almost simultaneously by Romieux, 7 who further speculated on the equilibrium between the weight of the elevated land mass and that of the total Areas of waters of the ocean, and deduced some interesting relathe cru st tions between them.
In the north and east it has numerous islands (St Lawrence, St Matthew, Nunivak and the Pribiloff group) and is shallow; in the south-west it reaches depths over 2000 fathoms. The seal-fisheries are important (see Bering Sea Arbitration).
Some of the " deeps " to which names have been given disappear or are divided into two or three smaller deeps when the contour lines representing hundreds of fathoms are translated into contour lines representing hundreds of metres.
A similar change in the contour lines may result from the substitution of lines in fathoms for those originally drawn in metres, and hence it is extremely desirable that specific names should only be given to such features as are pronounced enough to appear on maps drawn with either unit.
Aime estimated this depth at 150-200 fathoms, while the observations of the Austrian expedition in the eastern Mediterranean found it to be from 200 to nearly 400 fathoms. In the Red Sea, where a similar seasonal change occurs, the depth to which the surface layer warms up is about 275 fathoms. The great difference in salinity between the surface and the deep water excludes the possibility of effective convection in the seas of northern Europe, and in the open ocean the currents which are felt everywhere, and especially those with a vertical component, must exercise a very disturbing influence on convection.
If we assign to a column of water at the equator the density S-7-= 1.02 2 at the surface and 1.028 at l000 fathoms, or an average of 1.025, and to a column of water at the polar circle a mean density of i 028, there would result a difference of level equal to (1.028 - 1.025) X moo = 3 fathoms in a distance from the equator to the polar circle of some 4600 m.
From the little flea-like species, scarcely a tenth of an inch long, up to the great and rare but cosmopolitan Eurythenes gryllus, Lichtenstein, and the still larger Alicella gigantea, Chevreux, nearly half a foot long, captured by the prince of Monaco from a depth of 2936 fathoms, not one of these ubiquitous, uncountable hordes has ever been accused of assailing man.
From throwbacks to name brands, the array of toy options seems hundreds of miles wide and many fathoms deep.
The GMT, Fifty Fathoms, 500 Fathoms, Ultra-Slim, Flyback Chronograph, and Tourbillon are featured models of this collection.
The Sicilian-Ionian basin has a mean depth of 885 fathoms, and the Levant basin, 793 fathoms. Deep water is found close up to the coast of Sicily, Greece, Crete and the edge of the African plateau.
Another bank i ioo fathoms from the surface runs south from the east end of Crete, separating the Pola Deep from the depths of the Levant basin, in which a depth of 1960 fathoms was recorded near Makri on the coast of Asia Minor.
The mean depth over this ridge is about 250 fathoms, and the maximum depth nowhere reaches 500 fathoms. The main basin of the Atlantic is thus cut off from the Arctic basin, with which the area north of the ridge has complete deep-water communication.
This intermediate region, which has Atlantic characteristics down to 300 fathoms, and at greater depths belongs more properly to the Arctic Sea, commonly receives the name of Norwegian Sea.
In these troughs the depth is seldom much less than 3000 fathoms, and this is exceeded in a series of patches to which Murray has given the name of "Deeps."
Mean Karstens, 2047 fathoms. If we include the enclosed depth, and seas, the North Atlantic has a mean depth of 1800 bottom fathoms. The South Atlantic has a mean depth of deposits.
The furrows are the great ocean basins, and these would still persist even if the land surface were enlarged to the 1400 fathoms contour.
The portion nearest the log-ship is known as the "stray line"; its length varies from ro to 20 fathoms, but should be sufficient to ensure that the log-ship shall be outside the disturbing element of the ship's wake.