Volcanoes can be exciting and dangerous. They are also educational since they tell us a lot about the earth and even other planets. The inside of the Earth is very hot. Sometimes, this heat melts through the rock of the earth's crust, sending hot liquid rock (called magma) and gases onto the Earth's surface. A buildup of lava and ash around the area of an eruption becomes a volcano. Volcanoes can erupt for a very brief time or they can erupt many times over millions of years. Sometimes they sleep for long periods and people think they are finished, but they aren't. Mount St Helens was one of these sleeping volcanoes and it surprised everyone when it became active in 1980, causing a lot of destruction and loss of life.

Concepts

1. How are volcanoes formed?
2. How can they create islands?
3. What kind of destruction can they cause?
4. How do volcanoes affect our environment?
5. Where in the earth can you find active volcanoes?
6. Are there volcanoes on other planets?
7. What are the different types of volcanoes?

Terms To Learn