1. Volcanoes- Section 1 Volcanoes and Earth’s moving plates
Chapter 12
Volcanoes- Section 1
Volcanoes and Earth’s moving plates

2. Volcano Definition
A volcano is an opening in Earth that erupts gases, ash, and lava.
There are more than 600 active volcanoes.

3. Effects of Eruptions Lava destroys everything in its path.
Falling volcanic ash can collapse buildings, block roads, and potentially cause lung disease.
Sulfurous gas can be released. This can mix with water vapor resulting in acid rain.

4. Pyroclastic Flow
Pyroclastic flow- volcanic ash and debris flowing down the volcano.

5. How do volcanoes form?
They form from magma that reaches the surface of the Earth.
Vent- the opening in the Earth that allows the magma to flow out.
A crater- the steep walled depression around the volcano’s vent.

6. Where do volcanoes occur?
Divergent plate boundaries-Iceland is part of the Mid- Atlantic ridge so as the plates pull apart the magma reaches the surface.
Convergent plate boundaries- when an oceanic and continental plate subduct this allows for volcano formation.

7. Hot spots
The Hawaiian Islands formed far from plate boundaries but they formed from volcanic activity.
In some areas, it is thought that the Earth’s mantle and core are unusually hot.
Hot spot- hot rock at these areas is forced toward the crust where it melts partially to form a hot spot.

8. Hot spots