1. Volcanoes
Edited from original. Author Brent Swartz

2. What are volcanoes?
A volcano is an opening in Earth that erupts gases, ash, and lava.

3. How do volcanoes form?
Magma is less dense than the rock around it, so it is forced toward the surface
Vent: Opening in the Earth’s surface through which a volcanic eruption takes place
Crater: The steep-walled depression around a volcano’s vent at the summit of a volcano

4. Where do volcanoes occur?
A. Divergent Plate Boundaries
Iceland
Mid-Atlantic Ridge

5. Where do volcanoes occur?

6. Where do volcanoes occur?
B. Convergent Plate Boundaries
Oceanic Plate slides beneath Continental Plate
Example: Andes mountains in South America and Cascade mountains in USA
Erupt more violently
Oceanic Plate slides beneath Oceanic Plate
Example: Japan – forms Island Arcs

7. Where do volcanoes occur?

8. Where do volcanoes occur?

9. Where do volcanoes occur?

10. Where do volcanoes occur?

11. Where do volcanoes occur?

12. Where do volcanoes occur?
C. Hot Spots
Areas between Earth’s mantle and core that are unusually hot.
Hot rock forces toward the crust where it melts partially to form a hot spot.
Example: Hawaiian Islands
Pacific Plate moving over a stationary hot spot.

13. Hot Spot Occurrence

14. Where do volcanoes occur?

15. Liquid Hot Magma!!!!

16. Volcanic Activity Reports