1. Volcanic Eruptions

2. Anatomy of a Volcano

3. Volcanic Eruptions As magma rises, pressure decreases
Gases begin to expand
The force of expanding gases pushes magma from the magma chamber through the pipe until it flows or explodes out of the vent

4. Types of Eruptions Classified as Quiet and Explosive Quiet Explosive
Low in silica = low viscosity
Gases bubble out easily
Explosive
High in silica = High viscosity
Gases trapped in magma
Eruption breaks lava into fragments: ash to bombs
Pyroclastic flow is when explosive eruption mixture of hot gases, ash, cinders and bombs.

5. Life Cycle of Volcanoes
Active: Has, is or showing signs that it will erupt
Dormant: Show signs or predicted to erupt
Extinct: Unlikely to erupt again