sea-floor spreading


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sea-floor spreading

[′sē ¦flȯr ‚spred·iŋ]
(geology)
The hypothesis that the ocean floor is spreading away from the midoceanic ridges and is being conveyed landward by convective cells in the earth's mantle, carrying the continental blocks as passive passengers; the ocean floor moves away from the midoceanic ridge at the rate of 0.4 to 4 inches (1 to 10 centimeters) per year and provides the source of power in the hypothesis of plate tectonics. Also known as ocean-floor spreading; spreading concept; spreading floor hypothesis.
References in periodicals archive ?
So what if sea-floor spreading was a wrong hypothesis?
The Atlantic ocean would thus widen, in what came to be called sea-floor spreading, but its coasts would retain their shape from the time the continents were in contact.
The new analysis helps resolve the structure of the magma--or molten rock--reservoir that feeds sea-floor spreading at the ridge, the researchers report in the May 18 NATURE.