The first ledge rising from the ocean floor has depth averaging 8000 ft.
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."
The silica, in the form of diatom or radiolarian skeletons, is eventually deposited on the ocean floor after the death of the organisms. Most of the fine colloidal clay is, however, deposited as river-sludges when the fresh water carrying it mixes with denser sea-water.
The whole series was evidently deposited in shallow water on the summit of a submarine volcano standing in its present isolation, and round which the ocean floor has probably altered but a few hundred feet since the Eocene age.
Relief of the Ocean Floor.
While such steep mountain walls are found in the bed of the ocean it must be remembered that they are very exceptional, and except where there are great dislocations of the submarine crust or volcanic outbursts the forms of the ocean floor are incomparably gentler in their outlines than those of the continents.
Being protected by the water from the rapid subaerial erosion which sharpens the features of the land, and subjected to the regular accumulation of deposits, the whole ocean floor has assumed some approach to uniformity.
Still there are everywhere gentle inequalities on the smoothest ocean floor which give to its greater features a distinct relief.
Between the Seychelles and Sokotra (0° - 9 ° N.) there are great stretches of the ocean floor forming an almost level expanse at a depth of 2800 fathoms. The Arabian Gulf and Gulf of Aden are also very uniform with depths of about 1900 fathoms, while the floor of the Bay of Bengal rises very gradually northwards and is 1000 fathoms deep close up to the Ganges Shelf.
To this inconceivably slowly-growing deposit of inorganic material over the ocean floor there is added an overwhelmingly more rapid contribution of the remains of calcareous and siliceous planktonic and benthonic organisms, which tend to bury the slower accumulating material under a blanket of globigerina, pteropod, diatom or radiolarian ooze.
It also discusses electromagnetism, Solar magnetism, dynamo theory, ocean floor magnetization, and the magnetospheres of the Earth and the planets.
At low tide, guided walks of the ocean floor are led by naturalists.
grandest of scales and heads for the safety of the Ocean floor.
Geological oceanography is also concerned with sediment deposits, which can accumulate over millions of years on the ocean floor.
pipelines buried in the ocean floor.
rim of a submerged volcano, divers see trails of bubbles emitted from the ocean floor.
3 The areas of the continental shelf and lowlands are approximately equal, and it is an interesting circumstance that, taken as a whole, the actual coast-line comes just midway on the most nearly level belt of the earth's surface, excepting the ocean floor.
Between the Seychelles and Sokotra (0Ã‚° - 9 Ã‚° N.) there are great stretches of the ocean floor forming an almost level expanse at a depth of 2800 fathoms. The Arabian Gulf and Gulf of Aden are also very uniform with depths of about 1900 fathoms, while the floor of the Bay of Bengal rises very gradually northwards and is 1000 fathoms deep close up to the Ganges Shelf.
And beyond that, billions more ounces of gold may be buried beneath the ocean floor.
Along the rim of a submerged volcano, divers see trails of bubbles emitted from the ocean floor.
Harvesting oil from deep in the ocean floor can lead to accidental spills that harm ocean life and wetlands.
These circulations feed oxygen to the ocean floor giving the plants that grow there oxygen.
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