1. How magma forms
1. Temperature
2. Pressure
3. Addition of fluids

2. Lava Flows Pahoehoe – hot fluid lava Aa – forms sharp rock
Least viscous
Aa – forms sharp rock
Blocky – chunky rock
Most viscous

3. Types of Volcanoes
Cinder Cone – explosive eruptions
Tall and pointy

5. Calderas
Circular depression that forms when magma chamber below empties

8. The Ring of Fire Area of most active volcanoes
Area along the Pacific Ocean

21. Hot Spots
Area where lava comes through the crust as plates pass overtop
Away from plate boundaries