Volcanoes

The volcano Anak Krakatau erupting

Volcanoes are dramatic evidence of the powerful forces at work inside the Earth. Eruptions of ash, gas and lava destroy entire cities and kill large numbers of people.

Volcanoes also add nutrients to soils, creating perfect conditions for many crops. Some types of volcano make new sections of the tectonic plates that make up the surface of the Earth. Without volcanoes and our planet's plates, the dry land we live on would not be renewed, and weathering and erosion by water, wind and ice would eventually carry it all into the oceans leaving Earth a water world.

There are three common types of volcano: composite volcanoes, often the most deadly; shield volcanoes, which are large but generally less violent; and cinder cones.

Image: The Indonesian volcano Anak Krakatau erupts at night (credit: Getty Images/Tom Pfeiffer/VolcanoDiscovery)

Introduction

The volcano Anak Krakatau erupting Volcanoes

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