1. VOLCANOES AND PLATE TECTONICS
Awesome Eruptions

2. Where Do Volcanoes Occur?
Convergent plate boundaries: 75% of active volcanoes
Ex: Ring of Fire
Divergent plate boundaries: as plates move apart, magma rises to fill the space

3. Convergent Plate Boundaries
Ocean-Ocean
• Rising magma forms volcanic island arcs
(Aleutian Islands).
Ocean-Continent
• Rising magma forms continental volcanic arcs (Andes Mountains).

4. Divergent Plate Boundaries
greatest volume of volcanic rock is produced along the oceanic ridge system.

5. Intraplate volcanism is igneous activity that occurs within a tectonic plate away from plate boundaries.
• The activity forms localized volcanic regions called hot spots.

6. Hot Spots: volcano that occurs in the middle of a plate
Mantle plume rise from deep inside the mantle
An island will form if lava & ash build up
As the plate keeps moving, a “trail” develops (Hawaiian Islands)
OLDEST
oldest

7. Volcanoes Under the Ocean
Seamount: an underwater volcano
Look much like cinder/composite volcanoes
Black & White Smokers!

8. What appears to be the relationship between plate boundaries and Earthquake frequency?
Do you notice anything interesting about the locations of active volcanoes around the world?

9. Where Do Volcanoes Occur?
Recent Eruptions

10. In which of the following areas is a volcano least likely to form?
Divergent boundary
Convergent boundary
Transform boundary
Hot spot
Plates moving past each other does not necessarily lead to exposure of the mantle.