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Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor.These particles either have their origins in soil and rocks and have been transported from the land to the sea, mainly by rivers but also by dust carried by wind and by the flow of glaciers into the sea, or they are biogenic deposits from marine organisms or from ...
Polymetallic nodules were discovered in 1868 in the Kara Sea, in the Arctic Ocean of Siberia. During the scientific expeditions of HMS Challenger (1872–1876), they were found to occur in most oceans of the world. [10] Their composition varies by location, and sizeable deposits have been found in the following areas: Penrhyn Basin within the ...
A harbor or river bar is a sedimentary deposit formed at a harbor entrance or river mouth by the deposition of freshwater sediment or by the action of waves on the sea floor or on up-current beaches. Where beaches are suitably mobile, or the river's suspended or bed loads are large enough, deposition can build up a sandbar that completely ...
Red clay, also known as either brown clay or pelagic clay, accumulates in the deepest and most remote areas of the ocean. It covers 38% of the ocean floor and accumulates more slowly than any other sediment type, at only 0.1–0.5 cm/1000 yr. [1] Containing less than 30% biogenic material, it consists of sediment that remains after the dissolution of both calcareous and siliceous biogenic ...
The shelves make up less than 10% of the ocean, and a rough estimate suggests that only about 30% of the continental shelf sea floor receives enough sunlight to allow benthic photosynthesis. [ 36 ] Though the shelves are usually fertile, if anoxic conditions prevail during sedimentation, the deposits may over geologic time become sources for ...
Centralized in the oceans, this unique geological formation houses a collection of ridges, rifts, fault zones, and other geological features. [ 29 ] [ 30 ] The Mid-Atlantic Ridge is a consequence of the diverging North American and Eurasian , and the African and South American Plates . [ 31 ]
The benthic region of the ocean begins at the shore line (intertidal or littoral zone) and extends downward along the surface of the continental shelf out to sea.Thus, the region incorporates a great variety of physical conditions differing in: depth, light penetration and pressure. [5]
An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000 metres (9,800 and 19,700 ft).Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface.