1. Volcano Types and Eruptions
Ms. Sheehan YVHS
Geo-Science

2. Mr. Magner DHSHS Earth ScienceWords
Essential Qs!
Why are there two types of volcanic eruptions and how do they differ depending on the characteristics of their magma & location?

3. Warm Up: What is Viscosity, and what does it have to do with volcanic eruptions? What factors make lava or magma more/less viscous? Answer under essential questions…

4. A volcano is.. Your Objective: A weak spot in the crust where
molten material, or magma, comes
to the surface.

5. Magma vs. Lava
Magma – a molten mixture of rock-forming substances, gases, and water vapor from the mantle.
Lava – magma that has reached the surface of Earth

7. Location of Volcanoes Mr. Magner DHSHS Earth ScienceWords
There are about 600 active volcanoes on land and many more beneath the oceans.
Most volcanoes occur along diverging plate boundaries, such as the mid-ocean ridge, or in subduction zones around the edges of oceans.
Mr. Magner DHSHS Earth ScienceWords

8. Volcanoes at Converging Boundaries cont.
During oceanic and continental converging plates, mountainous volcanoes will form as in the Pacific Northwest of the United States
During two oceanic converging plates, Island arcs will form as in the Caribbean Islands