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Earth cross-section: composition, density, temperature

Draw a neat cross-section of the interior of the earth and mention the composition, density and temperature variation within the earth.

  Surface
  +-----------------------------+
  | Crust    5-70 km            |
  |-----------Moho--------------|
  | Mantle   to 2900 km         |
  |---------Gutenberg-----------|
  | Outer core  (liquid)        |
  | Inner core  (solid)         |
  +-----------------------------+
LayerDepth (km)CompositionDensity (g/cm³)Temperature
Crust0-10 (ocean) / 0-70 (continent)Granite (Si, Al) / basalt (Si, Mg)2.7-3.0Rises to about 500-900 °C at the base
Upper mantleto about 700Peridotite (Mg, Fe silicates)3.3-4.0About 1000-1500 °C
Lower mantle700-2900Dense Mg-Fe silicates and oxides4.0-5.5About 2000-3500 °C
Outer core2900-5150Liquid iron and nickel, some S/O9.9-12About 4000-5000 °C
Inner core5150-6371Solid iron and nickel12.8-13.5About 5000-6000 °C

Variations

  • Composition: changes from light silicate rocks outside to heavy metals inside.
  • Density: increases with depth due to compression and heavier materials, from 2.7 to about 13 g/cm³; the mean is 5.5.
  • Temperature: rises with depth. In the crust the geothermal gradient is about 25-30 °C per km; the rate drops below the crust, reaching about 5000-6000 °C at the centre.

✓ Answer checked by Claude Opus 5.5 (high effort)

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