What is a volcano?

A volcano is an opening in the Earth’s surface through which lava, ash and gases erupt. After many eruptions, lava or ash may build up forming a hill or mountain. Look at the picture below.

Mount Fuji is a large volcano found in Japan. (Photo by Alpsdake and used under this creative commons license.)

Volcanoes can be found on many Caribbean islands including St. Lucia, St. Vincent, Montserrat and Martinique. Much of the time, many volcanoes look just like ordinary hills or mountains. However, sometimes ash, gases and hot molten rock called lava from deep below the earth’s surface erupt from volcanoes. When this happens, it is called a volcanic eruption.

Lava is rock which is so hot it has melted. After lava erupts from a volcano, it cools down and becomes solid rock.

Sometimes volcanic eruptions send ash miles up into the air.

Quick volcano facts!

A volcano which is erupting now or has erupted in recent times is called an active volcano.
A volcano can go many years without erupting. A volcano which has not erupted in recent history is called a dormant volcano. A dormant volcano may erupt in the future.
If it is believed that a volcano will never erupt again then we call it an extinct volcano.