Global distribution of earthquakes and volcanoes

Earthquakes are located mostly in long, narrow belts, along all types of plate boundaries (or margins) as shown on this map.

[A] Most earthquakes happen along fault lines. [B] Most volcanoes appear on plate boundaries.

Volcanoes and earthquake activity often occur in similar places in narrow zones of activity, as shown on the map. These zones include:

  • the Pacific Ring of Fire around the Pacific Ocean
  • the Mid-Atlantic Ridge, a mid-ocean ridge that extends along the floor of the Atlantic Ocean
  • southern Europe

There are however some important exceptions. The Hawaiian Islands, which are entirely volcanic in origin, formed in the middle of the Pacific Ocean, more than 3,200 km from the nearest plate boundary. This is explained by the 'hotspot' theory.

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The 'hotspot' theory is that there are fixed spots in the mantle where magma rises to the surface. As the crust moves over these fixed spots, volcanoes are created, eventually forming a chain of volcanoes.
[A] Most earthquakes happen along fault lines. [B] Most volcanoes appear on plate boundaries.