According to the United States Geologic Survey, there are approximately 1,500 potentially active volcanoes worldwide. Most are located around the Pacific Ocean in what is commonly called the Ring of Fire. A volcano is defined as an opening in the Earth's crust through which lava, ash, and gases erupt. The term also includes the cone-shaped landform built by repeated eruptions over time.

Teach your students about volcanoes with this collection of engaging material.