1. INSIDE EARTH: CHAPTER 3- VOLCANOES
Section 1: Volcanoes and Plate Tectonics

2. What is a volcano?
Volcano - weak spot in the crust where molten material, or magma, comes to the surface

3. Magma - molten mixture of rock, gasses, and water from the mantle
What is a volcano?
Magma - molten mixture of rock, gasses, and water from the mantle

4. Lava- magma that reaches the surface
What is a volcano?
Lava- magma that reaches the surface

5. Location of volcanoes
There are about 600 active volcanoes on land. Many more lie below the sea.

6. Location of volcanoes
Ring of Fire: a major volcanic belt formed by many volcanoes at the edge of the Pacific Ocean

7. Location of volcanoes
Most volcanoes occur along diverging plate boundaries, such as the mid-ocean ridge or in subduction zones around the edges of oceans

8. Location of volcanoes
Many volcanoes occur on islands, near boundaries where two plate collide.

9. Location of volcanoes
The resulting volcanoes create a string of islands called an island arc.

10. Hot Spot Volcanoes
Some volcanoes result from “hot spots” in Earth’s mantle. A hot spot is a weak spot where magma from deep in the mantle melts through the crust like a blow torch.

11. Hot Spot Volcanoes
Hot spots often lie in the middle of continental or oceanic plates far away from plate boundaries.

12. Hot Spot Volcanoes
Can gradually form a series of volcanic islands, for example the Hawaiian Islands.

13. Hot Spot Volcanoes
The Hawaiian Islands formed over millions of years as the Pacific plate drifted over a hot spot.

14. Hot Spot Volcanoes
They can also form under the continents. An example of this is Yellowstone National Park in Wyoming.

15. Hot Spot Volcanoes
Yellowstone marks a major hot spot under the North American plate.