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The depth predicted by the square root of seafloor age found by the 1974 cooling mantle derivation [4] is too deep for seafloor older than 80 million years. [5] Depth is better explained by a cooling lithosphere plate model rather than the cooling mantle half-space. [5] The plate has a constant temperature at its base and spreading edge.
Marine geological studies were of extreme importance in providing the critical evidence for sea floor spreading and plate tectonics in the years following World War II. The deep ocean floor is the last essentially unexplored frontier and detailed mapping in support of economic ( petroleum and metal mining ), natural disaster mitigation, and ...
The surface gravitational field provides information on the dynamics of tectonic plates. The geopotential surface called the geoid is one definition of the shape of the Earth. The geoid would be the global mean sea level if the oceans were in equilibrium and could be extended through the continents (such as with very narrow canals). [12]
Depth is better explained by a cooling lithosphere plate model rather than the cooling mantle half-space. [27] The plate has a constant temperature at its base and spreading edge. Analysis of depth versus age and depth versus square root of age data allowed Parsons and Sclater [27] to estimate model parameters (for the North Pacific):
The episodic nature of the rollback is explained by a change in the density of the subducting plate, such as the arrival of buoyant lithosphere (a continent, arc, ridge, or plateau), a change in the subduction dynamics, or a change in the plate kinematics. The age of the subducting plates does not have any effect on slab rollback. [35]
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 ...
The combination of these processes continually recycles the ocean plate material. Most of the ocean floor is less than 100 million years in age. The oldest ocean plate is located in the Western Pacific, and has an estimated age of about 200 million years. By comparison, the oldest fossils found on land have an age of about 3 billion years. [21 ...
The environmental impact of deep sea mining is controversial. [39] [40] Environmental advocacy groups such as Greenpeace and the Deep Sea Mining Campaign [41] claimed that seabed mining has the potential to damage deep sea ecosystems and spread pollution from heavy metal-laden plumes. [42] Critics have called for moratoria [43] [44] or ...