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The lower mantle, historically also known as the mesosphere, represents approximately 56% of Earth's total volume, and is the region from 660 to 2900 km below Earth's surface; between the transition zone and the outer core. [1]
The upper curve is the line of liquidus, and the lower curve is the line of solidus. In chemistry , materials science , and physics , the liquidus temperature specifies the temperature above which a material is completely liquid, [ 2 ] and the maximum temperature at which crystals can co-exist with the melt in thermodynamic equilibrium .
The pressure at the bottom of the mantle is ≈140 GPa (1.4 Matm). [24] The mantle is composed of silicate rocks richer in iron and magnesium than the overlying crust. [25] Although solid, the mantle's extremely hot silicate material can flow over very long timescales. [26] Convection of the mantle propels the motion of the tectonic plates in the
By mole fraction (i.e., by quantity of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other trace gases (see Composition below for more detail). Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
Mantle convection is the result of a thermal gradient: the lower mantle is hotter than the upper mantle, and is therefore less dense. This sets up two primary types of instabilities. In the first type, plumes rise from the lower mantle, and corresponding unstable regions of lithosphere drip back into the mantle.
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]
A vapor can exist in equilibrium with a liquid (or solid), in which case the gas pressure equals the vapor pressure of the liquid (or solid). A supercritical fluid (SCF) is a gas whose temperature and pressure are above the critical temperature and critical pressure respectively. In this state, the distinction between liquid and gas disappears.
Upwelling mantle material can add to the crust at mid oceanic ridges. Fluids can extract carbon from the mantle and erupt in volcanoes. At 330 km deep a liquid consisting of carbon dioxide and water can form. It is highly corrosive, and dissolves incompatible elements from the solid mantle. These elements include uranium, thorium, potassium ...