1. VOLCANOES

2. Do now 4/23/12 What do you already know about Volcanoes?
Are all volcanoes the same?
What can happen to cities (buildings, people, land)?

3. Volcanoes
Volcanoes are openings in the Earth that erupt gases, ash, and lava.

4. EFFECTS OF ERUPTIONS 1. Cloud of ash & dust Mayon Volcano
Phillipines 1994

5. EFFECTS OF ERUPTIONS
2. Lava flow
Krafla, Iceland 1984
Kilauea, Hawaii

6. EFFECTS OF ERUPTIONS 3. Avalanches, landslides, tsunamis
Chile, South America
Aleutian Islands, Alaska

9. EFFECTS OF ERUPTIONS 4. Destruction of land & communities
Mt. St. Helens
USA
Pompeii, Italy

11. Occurrence
Divergent plate boundaries – plates spread apart and magma rises
Example = Mid Atlantic Ridge

12. Occurrence
Convergent Plate Boundaries – plates come together, crust sinks, melts, and rises
Example = Andes Mountain Range

13. Occurrence
Hot Spots – occur in the middle of a plate due to a weak spot in the crust
Example = Hawaiian Islands

14. Hawaiian volcanoes

16. WHAT CONTROLS ERUPTIONS?
1. Amount of gas: More gas build up = bigger explosion
2. Compositiomore n of Lava: Heavy Lava = destruction & damage

17. Types of Volcanoes
Shield

18. Shield Volcano

19. Types of Volcanoes
Composite

20. Composite volcano
Popocatepetl, Mexico

21. Types of Volcanoes
Cinder

22. Cinder volcano