1. Reservoir of molten rock beneath a volcano

1. Hot molten rock beneath the Earth's surface

2. A mass of volcanic ash and gases suspended in the air

3. The deposition of volcanic ash on the ground

4. Violent release of magma, gases, and ash from a volcano

5. Gases released during a volcanic eruption

6. A volcano that is not currently erupting

7. Molten rock expelled by a volcano

8. A fine-grained volcanic rock with high silica content

9. Large volcanic depression usually formed after a massive eruption

10. Column of volcanic gases, ash, and steam rising from a vent

11. An area of the Earth's surface where volcanic activity occurs

12. Fast-moving mixture of water and volcanic debris

13. A long crack in the Earth's surface caused by volcanic activity

14. A yellow mineral often found near volcanic vents

15. Loose material ejected from a volcano during eruption

16. Potential threat posed by volcanic activity

17. Small volcanic fragment ejected during an eruption

18. Volcanic debris that varies in size