Plate tectonic theory – WJEC Global distribution of earthquakes and volcanoes
Earthquakes and volcanic eruptions affect people all over the world. They are caused by the movement of tectonic plates. Tectonic hazards can destroy buildings, infrastructure and cause deaths.
Earthquakes are located mostly in long, narrow belts, along all types of plate boundaryThe region where two or more tectonic plates meet. It is a zone of intense seismic activity.(or margins) as shown on this map.
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, but are located more than 3,200 kilometres from the nearest plate boundary. This is explained by the 'hotspot' theory.
The Pacific Ring of Fire can be clearly seen on the map. Over 450 of the world’s active and dormant volcanoes are located here, but this area is also highly active in terms of earthquakes. About 90 per cent of all earthquakes happen in and around the Pacific Ring of Fire.