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upper mantle
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Figure 15: Schematic cross section illustrating the shell structure of the Earth. Cross-sectional diagram of Earth's outer layers, showing oceanic and continental crust at the surface, the rigid lithosphere, the partially melted asthenosphere, and transitions from upper to lower mantle, with labeled depths and rock properties.
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upper mantle

Earth science
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Figure 15: Schematic cross section illustrating the shell structure of the Earth.
Figure 15: Schematic cross section illustrating the shell structure of the Earth.

The Earth's upper mantle is a crucial layer lying beneath the lithosphere, extending from about 100 km to 700 km below the surface. This region is hotter and more fluid than the lithosphere, with heat from Earth's interior keeping it malleable.1

Processes within the upper mantle significantly influence the Earth's surface. Convection currents here are believed to drive the movement of tectonic plates. These currents also cause magma to rise through volcanic vents and spreading centers, creating new crust. Additionally, the upper mantle is a source of earthquakes when convection currents stress the lithosphere above. Volcanic eruptions and some earthquakes originate from processes within this layer, and it plays a role in concentrating elements that can form ore deposits.123

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7 Britannica Sources
  1. chemical element - The Earth’s mantle
  2. asthenosphere
  3. plate tectonics - Earth’s layers
  4. How Do Tectonic Plates Move?
  5. plate tectonics - Mantle convection
  6. plate tectonics - Seismic tomography
  7. igneous rock - Origin of magmas

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