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Geography

Volcanoes and volcanic eruptions

Volcanoes form when magma reaches the Earth's surface. The immediate effects can be devastating, but they can be beneficial in the long term. Watch this video to find out more.

Video

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Key points

  • Volcanic eruptions can happen at destructive and constructive boundaries. Volcanoes form when magma rises through cracks or weaknesses in the Earth's crust.
  • Pressure builds and magma explodes to the surface causing a volcanic eruption. The lava from the eruption cools to form new crust. After several eruptions, the rock builds up to form a volcano.
  • The magma chamber is a collection of magma below the volcano.
  • The main vent and secondary vent are where the magma escapes.
  • Active volcanoes erupt frequently.
  • Dormant volcanoes are temporarily inactive.
  • Extinct volcanoes are never likely to erupt again.

All Geography videos

Natural hazards index

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