1. 8.2 Notes Types of Volcanoes

2. Key Concept: Tectonic Plate Motions can result in volcanic activity at plate boundaries Which boundary has explosive volcanoes? Why? Which boundary has explosive volcanoes? Why? Which boundary has nonexplosive (quiet runny lava) volcanoes? Why? Which boundary has nonexplosive (quiet runny lava) volcanoes? Why?

3. What is the difference between magma and lava? What is the difference between magma and lava? Lava is magma once it reaches Earth’s surface Lava is magma once it reaches Earth’s surface 4 types of lava: 4 types of lava: 1. Aa 2. Pahoehoe 3. Pillow lava 4. Blocky lava

5. There are 3 types of Volcanoes Shield volcano Shield volcano Cinder cone volcano Cinder cone volcano Composite volcano Composite volcano

6. Shield Volcanoes Usually form at hot spots Usually form at hot spots Form from many layers of nonexplosive eruptions (quiet flows of lava) Form from many layers of nonexplosive eruptions (quiet flows of lava) The lava is very runny, so it spreads over a wide area The lava is very runny, so it spreads over a wide area Gently sloping sides – not steep Gently sloping sides – not steep Very large (meaning wide – not tall) Very large (meaning wide – not tall)

7. Cinder Cone Volcanoes Smallest type of volcano Smallest type of volcano Most common type of volcano Most common type of volcano Made of pyroclastic material Made of pyroclastic material Moderately explosive eruptions Moderately explosive eruptions Steep sides Steep sides Wide summit crater Wide summit crater Usually only erupts once Usually only erupts once

8. Composite Volcanoes Also known as a stratovolcano Also known as a stratovolcano Most recognizable of all volcanoes Most recognizable of all volcanoes Form from both explosive eruptions and quieter flows of lava Form from both explosive eruptions and quieter flows of lava Broad base and steep sides Broad base and steep sides Erupts many times (every hundred years or so) Erupts many times (every hundred years or so)