Volcano

Volcano

A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

Etymology

The word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology.

Plate tectonics

Volcanoes are usually located 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.

Types of volcanoes

Volcanoes can be described as either active, dormant, or extinct. An active volcano is one that has had an eruption in the past 10,000 years. A dormant volcano is one that has not erupted in the past 10,000 years, but which is expected to erupt again. An extinct volcano is one that scientists consider unlikely to erupt again.

Volcanic features

The features of volcanoes are much more complicated and their structure and behavior depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as craters and vents.

Volcanic activity

Volcanic activity can be of three types: explosive, effusive, or a mixture of these two.

Volcanic effects

Volcanic eruptions can cause earthquakes, fast floods, mud slides, and rock falls. Longer-term effects can include changes to the climate and even mass extinctions of species.

See also

• List of volcanoes
• Volcanology

External links

• Global Volcanism Program - Smithsonian Institution

Volcano Resources
Latest articles Most recent articles Ongoing trials	Wikipedia