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The Earth core's heat flow—heat leaving the core and flowing into the overlying mantle—is thought to be due to primordial heat, and is estimated at 5–15 TW. [23] Estimates of mantle primordial heat loss range between 7 and 15 TW, which is calculated as the remainder of heat after removal of core heat flow and bulk-Earth radiogenic heat ...
In the mantle, temperatures range from approximately 500 K (230 °C; 440 °F) at the upper boundary with the crust to approximately 4,200 K (3,900 °C; 7,100 °F) at the core-mantle boundary. [21] The temperature of the mantle increases rapidly in the thermal boundary layers at the top and bottom of the mantle, and increases gradually through ...
The potential temperature of the mantle is estimated to be about 1350 C today. There is an analogous potential temperature of the core but since there are no samples from the core its present-day temperature relies on extrapolating the temperature along an adiabat from the inner core boundary, where the iron solidus is somewhat constrained.
Earth cutaway from core to exosphere Geothermal drill machine in Wisconsin, USA. Temperature within Earth increases with depth. Highly viscous or partially molten rock at temperatures between 650 and 1,200 °C (1,200 and 2,200 °F) are found at the margins of tectonic plates, increasing the geothermal gradient in the vicinity, but only the outer core is postulated to exist in a molten or fluid ...
The temperature of the inner core can be estimated from the melting temperature of impure iron at the pressure which iron is under at the boundary of the inner core (about 330 GPa). From these considerations, in 2002, D. Alfè and others estimated its temperature as between 5,400 K (5,100 °C; 9,300 °F) and 5,700 K (5,400 °C; 9,800 °F). [ 5 ]
Earth's outer core is a fluid layer about 2,260 km (1,400 mi) thick, composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. [ 1 ] [ 2 ] [ 3 ] The outer core begins approximately 2,889 km (1,795 mi) beneath Earth's surface at the core-mantle boundary and ends 5,150 km (3,200 mi) beneath Earth's surface ...
The definition of the LAB as a thermal boundary layer (TBL) comes not from temperature, but instead from the dominant mechanism of heat transport. The lithosphere is unable to support convection cells because it is strong, but the convecting mantle beneath is much weaker.
As a result, the lower mantle's temperature gradient as a function of depth is approximately adiabatic. [1] Calculation of the geothermal gradient observed a decrease from 0.47 kelvins per kilometre (0.47 °C/km; 1.4 °F/mi) at the uppermost lower mantle to 0.24 kelvins per kilometre (0.24 °C/km; 0.70 °F/mi) at 2,600 kilometres (1,600 mi). [3]