VOLCANIC ACTIVITY

Photo credit: Davíð Einarsson

A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot magma, ash and gases to escape from below the surface. Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together.

By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth’s crust (called “non-hotspot intraplate volcanism”), such as in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America