Search results
Results from the WOW.Com Content Network
Earth's inner core is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 20% of Earth’s radius or 70% of the Moon 's radius. [1][2] There are no samples of Earth's core accessible for direct measurement, as there are for Earth's mantle. [3]
Geothermal gradient. Temperature profile of inner Earth, schematic view (estimated). The red dashed line shows the minimum temperature for the respective mantle rock to melt. The geothermal gradient remains below the melting temperature of the rock, except in the asthenosphere. Sharp rises occur in the uppermost mantle and at the core–mantle ...
Earth's inner core is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 19% of Earth's radius [0.7% of volume] or 70% of the Moon 's radius. [32][33] The inner core was discovered in 1936 by Inge Lehmann and is generally composed primarily of iron and some nickel.
The largest values of heat flux coincide with mid-ocean ridges, and the smallest values of heat flux occur in stable continental interiors. Earth's internal heat budget is fundamental to the thermal history of the Earth. The flow heat from Earth's interior to the surface is estimated at 47±2 terawatts (TW) [1] and comes from two main sources ...
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.
Lithosphere–asthenosphere boundary. A diagram of the internal structure of Earth. The lithosphere consists of the crust and upper solid 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.
Earth's layered structure: (1) inner core; (2) outer core; (3) lower mantle; (4) upper mantle; (5) lithosphere; (6) crust Earth science generally recognizes four spheres, the lithosphere , the hydrosphere , the atmosphere and the biosphere [ 3 ] as correspondent to rocks , water , air and life respectively.
Earth's inner core may be rotating at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1–0.5° per year, although both somewhat higher and much lower rates have also been proposed. [133] The radius of the inner core is about one-fifth of that of Earth. The density increases with depth.