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The high pressure in the lower mantle has been shown to induce a spin transition of iron-bearing bridgmanite and ferropericlase, [5] which may affect both mantle plume dynamics [6] [7] and lower mantle chemistry. [5] The upper boundary is defined by the sharp increase in seismic wave velocities and density at a depth of 660 kilometers (410 mi). [8]
The upper mantle of Earth is a very thick layer of rock inside the planet, which begins just beneath the crust (at about 10 km (6.2 mi) under the oceans and about 35 km (22 mi) under the continents) and ends at the top of the lower mantle at 670 km (420 mi). Temperatures range from approximately 500 K (227 °C; 440 °F) at the upper boundary ...
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. [4] The Earth's lithosphere rides atop the asthenosphere, and the two form the components of the upper mantle ...
The mantle is divided into upper and lower mantle [21] separated by a transition zone. [22] The lowest part of the mantle next to the core-mantle boundary is known as the D″ (D-double-prime) layer. [23] The pressure at the bottom of the mantle is ≈140 GPa (1.4 Matm). [24]
The transition zone is the part of Earth's mantle that is located between the lower and the upper mantle, most strictly between the seismic-discontinuity depths of about 410 to 660 kilometres (250 to 410 mi), but more broadly defined as the zone encompassing those discontinuities, i.e., between about 300 and 850 kilometres (190 and 530 mi) depth. [1]
Plates in the crust of Earth. Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume.It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper part of the mantle. [1]
The internal structure of Earth. Earth's mantle is a layer of silicate rock between the crust and the outer core.It has a mass of 4.01 × 10 24 kg (8.84 × 10 24 lb) and makes up 67% of the mass of Earth. [1]
These must be corrected for degassing of carbon and other elements. Since the Earth formed, the upper mantle has lost 40–90% of its carbon by evaporation and transport to the core in iron compounds. The most rigorous estimate gives a carbon content of 30 parts per million (ppm). The lower mantle is expected to be much less depleted – about ...