The terrace closest to the land, known as the continental shelf, has an average depth of 600 ft., and connects Australia, New Guinea, and Tasmania in one unbroken sweep. Compared with other continents, the Australian continental shelf is extremely narrow, and there are points on the eastern coast where the land plunges down to oceanic depths with an abruptness rarely paralleled.
Off the Queensland coast the shelf broadens, its outer edge being lined by the seaward face of the Great Barrier Reef.
From Torres Strait to Dampier Land the shelf spreads out, and connects Australia with New Guinea and the Malay Archipelago.
An elongation of the shelf to the south joins Tasmania with the mainland.
Shelf, or show evidence in the character of their rocks of Islands having at one time been continuous with a neighbouring continent.
Been made to arrive at a definite international agreement on this subject, and certain terms suggested by a committee were adopted by the Eighth International Geographical Congress at New York in 1904.4 The forms of the ocean floor include the " shelf," or shallow sea margin, the " depression," a general term applied to all submarine hollows, and the " elevation."
" I am not conscious," says he, " of having ever bought a book from a motive of ostentation; every volume, before it was deposited on the shelf, was either read or sufficiently examined "; he also mentions that he soon adopted the tolerating maxim of the elder Pliny, that no book is ever so bad as to be absolutely good for nothing.
Retrotabulum), a term of ecclesiastical art and architecture, applied in modern English usage to an altar-ledge or shelf, raised slightly above the back of the altar or communion table, on which are placed the cross, ceremonial candlesticks and other ornaments.
Gulfs formed by the overflowing of depressed lands lie upon the continental shelf, e.g.
Amongst the best known of the furrows of the continental shelf are the Cape Breton Deep, in the Bay of Biscay, the Hudson Furrow, southward of New York, the so-called Congo Canon, the Swatch of No Ground off the Ganges delta, the Bottomless Pit off the Niger delta, and numerous similar furrows on the west coast of North America and outside the fjords of Norway, Iceland and the west of Scotland, as well as in the.
The seaward edge of the continental shelf often falls steeply to the greatest depths of the ocean, and not infrequently forms the slope of a trench, a form of depression which has usually a steep slope towards a continent or an island-bearing rise on one side and a gentler slope towards the general level of the ocean on the other.
In the saint's cave on the shore may be seen the rocky shelf on which he made his bed, but his remains were interred in the hamlet of Clachan, some 2 m.
"The articles manufactured from jute are principally (I) gunny bags; (2) string, rope and cord; (3) kampa, a net-like bag for carrying wood or hay on bullocks; (4) chat, a strip of stuff for tying bales of cotton or cloth; (5) dola, a swing on which infants are rocked to sleep; (6) shika, a kind of hanging shelf for little earthen pots, &c.; (7) dulina, a floor-cloth; (8) beera, a small circular stand for wooden plates used particularly in poojahs; (9) painter's brush and brush for white-washing; (io) ghunsi, a waist-band worn next to the skin; (II) gochh-dari, a hair-band worn by women; (12) mukbar, a net bag used as muzzle for cattle; (13) parchula, false hair worn by players; (14) rakhi-bandhan, a slender arm-band worn at the Rakhi-poornima festival; and (15) dhup, small incense sticks burned at poojahs."
Here is Meintjes Kop, with a broad natural shelf midway below the summit.
Where the French telegraph cable between Brest and New York passes from the continental shelf of the Bay of Biscay to the depths of the Atlantic the angle of slope is.
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.
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.
In the Indian Ocean the Kerguelen Rise stretches broadly southward, east of the island which gives it a name, to the Antarctic Shelf with the greatest depths upon it usually less than 2000 fathoms, and it stretches northward beyond New Amsterdam to 30° S.
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.
Right up to the Antarctic Shelf, with depths ranging down to 2500-3000 fathoms, and communicating with the main Pacific Basin to the east of New Zealand.
The Austral-Asiatic or Malay Sea is occupied by a great shelf in the region west of Borneo and north of Java, while in the east there are eight abruptly sunk basins of widely different size.
The Black Sea, connected with the Mediterranean by long and narrow channels, is occupied in the north by an extensive shelf on which Mean Depths of Oceans and Seas.
Towards the continent there is a broad shelf, and just before the chain of islands separating them from the ocean runs a narrow and deep trough.
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.
Recent limestones are being produced in this way and also in some places by the precipitation of calcium carbonate by sodium or ammonium carbonate which has been carried into the sea or formed by organisms. The precipitated carbonate may agglomerate on mineral or organic grains which serve as nuclei, or it may form a sheet of hard deposit on the bottom as occurs in the Red Sea, off Florida, and round many coral islands in the Pacific. Only the sand and the finest-grained sediments of the shore zone are carried outwards over the continental shelf by the tides or by the reaction-currents along the bottom set up by on-shore winds.
The very finest sediment is kept in a state of movement until it drops into the gulleys or furrows of the shelf, where it can come to rest together with the finer fragments of the remains of littoral or bank vegetation.
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.
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.
Between Madeira and the Biscay Shelf, i.e.
The materials are fed in at the top of the shoot and fall from shelf to shelf, the mixing being effected by the various shocks thus given.
He steers it towards a shelf of rock, called in Russ's time Tell's Platte, springs on shore, shoots the bailiff dead with his crossbow, and goes back to Uri, where he stirs up the great strife which ended in the battle of Morgarten.