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Mantle convection is the very slow creep of Earth's solid silicate mantle as convection currents carry heat from the interior to the planet's surface. [ 2 ] [ 3 ] Mantle convection causes tectonic plates to move around the Earth's surface.
Layered-mantle convection proponents hold that the mantle's convective activity is layered, separated by densest-packing phase transitions of minerals like olivine, garnet and pyroxene to more dense crystal structures (spinel and then silicate perovskite and post-perovskite). Slabs that are subducted may be negatively buoyant as a result of ...
In the second type, subducting oceanic plates (which largely constitute the upper thermal boundary layer of the mantle) plunge back into the mantle and move downwards towards the core-mantle boundary. Mantle convection occurs at rates of centimeters per year, and it takes on the order of hundreds of millions of years to complete a cycle of ...
Earth's crust and mantle, Mohorovičić discontinuity between bottom of crust and solid uppermost mantle. Earth's mantle extends to a depth of 2,890 km (1,800 mi), making it the planet's thickest layer. [20] [This is 45% of the 6,371 km (3,959 mi) radius, and 83.7% of the volume - 0.6% of the volume is the crust].
A diagram of the internal structure of Earth. The lithosphere consists of the crust and upper solid mantle (lithospheric mantle). The green dashed line marks the LAB. The lithosphere–asthenosphere boundary (referred to as the LAB by geophysicists) represents a mechanical difference between layers in Earth's inner structure.
Radiogenic heat production in the mantle is linked to the structure of mantle convection, a topic of much debate, and it is thought that the mantle may either have a layered structure with a higher concentration of radioactive heat-producing elements in the lower mantle, or small reservoirs enriched in radioactive elements dispersed throughout ...
Almost all radiation from the sun is emitted from this layer, which has a temperature of 8,100 to 11,000 degrees. ... the hot, dense plasma moved in ways not unlike magma in Earth's mantle, which ...
Dashed curve: Layered mantle convection; Solid curve: Whole mantle convection. [ 25 ] The most prominent thermal contrast known to exist in the deep (1000 km) mantle is at the core-mantle boundary at 2900 km. Mantle plumes were originally postulated to rise from this layer because the "hot spots" that are assumed to be their surface expression ...