1. If you need help, look in your notes or your textbook!
Warm-Up Review
Describe how the Andes Mountains in South America were formed. Use the words:
Continental crust
Oceanic crust
Convergent boundary
If you need help, look in your notes or your textbook!

2. Vulcan- Roman God of Fire
Volcanoes
Vulcan- Roman God of Fire

3. What is a volcano?
Volcano- Areas of Earth’s surface through which magma and volcanic gases pass

4. What’s inside a volcano?
Magma Chamber- molten rock that feeds a volcano
Vents- cracks in the crust
What is the difference between magma and lava?

5. Types of Volcanoes Shield volcano Cinder cone volcano
Composite volcano

6. 1. Shield Volcano Built from layers of lava Non-explosive eruptions
Not very steep, but can be big
Example: Hawaiian Islands

7. 2. Cinder Cone Volcano Built from pyroclastic material
Moderately explosive, short eruptions
Small in size, steep slopes
Example: Mount Etna in Italy

8. 3. Composite Volcano Most common type
Explosive eruptions and lava flow
Built from pyroclastic material AND lava
Example: Many volcanoes within the Ring of Fire

11. Factors Affecting Eruptions
Magma composition
Viscous magma (maple syrup) has more violent eruptions that less viscous magma (more watery)
Magma temperature
Hotter magma flows easier so less violent eruptions
Amount of dissolved gases
The more dissolved gases, the more violent the eruptions

12. What Erupts from a Volcano?
Blocky lava
Lava can be
thick or thin.
Pahoehoe Aa
Pillow lava

13. What Erupts from a Volcano?
Pyroclastic material
Rock fragments created by eruptions
EXPLOSIVE
Lapilli
Volcanic bombs
Volcanic blocks
Volcanic ash

14. How do volcanoes affect the Earth?
Flows and Fallouts
hot ash can flow really quickly
Knock down buildings
Dam rivers (flooding/drought)
Kill crops and livestock
Climatic Changes
Ash & Gases can block sunlight
Drop average global temperature noticeably

15. Craters, Calderas, and Lava Plateau
From explosions of material out of the vent and the collapse of material back into vent
Caldera
Much larger depression that forms when magma chamber empties and its roof collapses
Lava Plateau
Forms when lava erupts from long cracks, or fissures, and spreads out evenly (thousands of km)

16. What causes volcanoes? Tectonic Plate Boundaries!!!
There are lots of uncertainties about why volcanoes form, because scientists have to rely on models based on rock samples and other data.
~75% world’s active volcanoes in Ring of Fire

17. How do volcanologists predict eruptions?
Measuring Small Quakes
Before eruption, increase in number & intensity
Measuring Slope
Bulges may form with magma (tiltmeter)
Measuring Volcanic Gases
Outflow of volcanic gases
Sulfur dioxide, carbon dioxide
Measuring Temperature from Orbit
Measure changes in temperature over time

18. You should not be a Volcanologist if….
You don’t like hiking, backbacking, rockclimbing, etc.
You are not interested in experiencing extreme temperatures and heights.
If you don’t like to travel to incredible places and see breathtaking views of the world.