1. Volcanoes Chapter 6

2. What are volcanoes? They are openings in the Earth that erupt gases, ash, and lava

3. Kilauea – most active volcano in the world

4. Effects of eruptions: - volcanic ash (global temp.) -Lava flows -Fires -Lahars (mudslides) -Acid rain

5. Formation Magma is forced upward towards the Earth’s surface (WHY?) Flows out through openings called VENTS

7. Where do they occur? Divergent Plate boundaries Iceland

8. Convergent plate boundaries Andes Mountains – South America

9. Hot Spots The Hawaiian IslandsThe Hawaiian Islands

10. Types of Eruptions Based on - amount of water vapor or other gases trapped in magma - Silica content of magma

11. Quiet Eruptions Basaltic magma Iceland Kilauea

12. Explosive Eruptions Granitic & Andesitic Magma Mt. St. Helens Soufriere Hills Mt. Pinatubo Mt. Pinatubo

13. Forms of Volcanoes Shield Volcanoquiet eruptions of basaltic magma layering to form broad volcanoes with sloping sides Shield Volcano – quiet eruptions of basaltic magma layering to form broad volcanoes with sloping sides

14. Cinder Cone Cinder Cone – Explosive eruptions of tephra which form steep sided, loosely packed volcanoes

15. Composite Volcano – A combo of quiet and violent eruptions usually steep