1. Volcanoes

2. Parts of a Volcano – Illustrate on Blank Page
Vent - the opening of the volcano where the magma escapes.
Conduit – The vertical movement of magma. Connects vent to magma chamber
Magma Chamber – Storage of magma beneath the volcano.
Sill – Horizontal movement of magma

3. #1 #2 #3 #4

4. What causes an eruption? (Blank Page)
During an eruption, melted rock called magma leaves the magma chamber and moves up the conduit. The magma leaves the conduit at the vent.
Magma is called lava after it leaves the vent.

5. Put your blank sheet to the side and get out your tan sheet of paper
Put your blank sheet to the side and get out your tan sheet of paper. Then discuss with your partner what this picture is showing.

6. Shield Volcano (Tan Sheet)
Eruption Style – low gas content, gentle eruptions, non-threatening lava flows
Magma Chemistry – Low silica  Flows easily like maple syrup.
Physical Appearance – Large, gentle slopes, wide. The low silica magma can’t build up so the it forms very wide, but relatively short volcanoes.
Location- Found at HOT SPOTS and DIVERGENT BOUNDARIES

7. Composite Volcano (Tan Sheet)
Eruption Style – High Amounts of Built Up Gas leads to explosive eruptions
Magma Chemistry – high silica – sticky magma that has a consistency of peanut butter. Thick and sticky
Physical Appearance – Large volcanoes that have tall steep sides. This volcano the magma can build up tall sides because the magma sticks together. Builds up rather than out.
Location- Found at CONVERGENT BOUNDARIES

8. Cinder Cone Volcano (Tan Sheet)
Eruption Style – Moderately Explosive, high gas content
Magma Chemistry – High Silica, Makes pyroclasts, Scoria,
Physical Appearance – Small, steep sides, made of loose rock fragments that build around eruption
Location – Forms on and around existing volcanoes, Usually only erupt once

9. Put your tan sheet to the side and get out your PURPLE sheet of paper
Put your tan sheet to the side and get out your PURPLE sheet of paper. Then discuss with your partner what this picture is showing.

10. Volcano at a Convergent Boundary (Purple Sheet)
When two plates collide, the denser plate subducts and sinks back into the mantle.
As the plate sinks, thermal energy below the surface melts the mantle and forms magma
Erupting magma forms a Volcano.
Composite Volcanoes are found at Convergent Boundaries

11. Volcano at a Divergent Boundary (Purple Sheet)
When plates separate, magma rises through the opening.
When magma erupts on the ocean floor, new oceanic crust forms.
New oceanic crust forms from magma that erupts onto the ocean floor.

12. Volcano at a Hot Spot (Purple Sheet)
As a tectonic plate moves over a plume, a new volcano forms.
As the volcano moves away from the hot spot, it becomes inactive or dormant.
As a result, of this continual movement, a chain of volcanoes form.

13. Volcano at a Hot Spot (Purple Sheet)

14. Put your purple sheet to the side and get out your BLANK sheet of paper. Then discuss with your partner what this picture is showing.

15. How are Volcanoes Predictable based on frequency, location, and eruption.
Discuss With you partner and write down your ideas
Location –
Eruption –

16. How are Volcanoes Predictable based on frequency, location, and eruption.
Shield Volcanoes are constantly erupting. Hawaii grows
When volcanic gas emissions increases. This shows that magma is moving towards the surface of the earth and is forcing the gases out as it rises.
Series of small earthquakes indicate magma movement that could trigger an eruption
Location –
Almost all volcanoes can be explained by plate boundaries.
Composite Volcanoes form at Convergent Boundaries
Shield Volcanoes form at Divergent Boundaries
Ground Deformation – often times before an volcano will erupt you can see the “skin” of the volcano moving up and down before the eruption.
Eruption –
Composite Volcanoes have steep sides that build up gases to have explosive eruptions.
Shield Volcanoes are constantly erupting and growing with gentle eruptions

17. How are Volcanoes Unpredictable
Frequency –
Discuss With you partner and write down your ideas
Location –
Eruption –

18. How are Volcanoes Unpredictable -
Volcanologists can reasonably predict when an eruption is about to occur, they still cannot reliably estimate the eruption's size, explosiveness or exact nature
Frequency –
Guadeloupe Island Evacuation – 73,000 people were evacuated for over 3 months No significant eruption ever occurred.
Cinder Cones usually happen only once, but can go from days to years.
Location –
Hot Spot volcanoes are volcanoes that form in the middle of the plate.
Cinder Cones Volcanoes form on existing volcanoes due to a build up of gases being released.
Eruption -
1980s Mount St. Helens Lateral Blast

19. 1. Shield, Cinder Cone, or Composite

20. 2. Shield, Cinder Cone, or Composite

21. 3. Shield, Cinder Cone, or Composite

22. 4. Shield, Cinder Cone, or Composite
Volcanoes that form at Divergent Boundaries

23. 5. Shield, Cinder Cone, or Composite
Volcanoes that form at Convergent Boundaries

24. 6. Shield, Cinder Cone, or Composite
Volcanoes that form at Hot Spots in the middle of a plate

25. 7. Shield, Cinder Cone, or Composite
During an eruption lava shoots out of the ground, falls around the opening, and then cools. The cooled pieces of lava are called pyroclasts. The pyroclasts pile up and form a hill with an opening called a crater in the center.
These volcanoes are the smallest type of volcano. They form on the surface of larger volcanoes. Usually they do not erupt very long.

26. 8. Shield, Cinder Cone, or Composite
These type of volcanoes, are built almost entirely of fluid lava flows. Flow after flow pours out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat shape, with a profile much like that of a warrior's shield.
An example of this type of volcano is the Hawaiian Islands. Hawaii has formed over a hot spot in the middle of the Pacific Ocean. The Pacific Ocean has drifted over this hot spot creating a string of volcanic islands.
These volcanoes can form over hot spots in the middle of plates or at divergent plate boundaries. The magma that forms these volcanoes from the mantle.

27. 9. Shield, Cinder Cone, or Composite
These volcanoes form in subduction zones when an oceanic plate subducts beneath a continental plate. The sticky high silica magma creates steep-sided towering volcanoes. These volcanoes can lie dormant for hundreds of years, but can become alive with very destructive and explosive eruptions.
Most of the Earth's active volcanoes have formed a ring around the Pacific Ocean. There are 452 of these volcanoes in the Pacific Ring of Fire. The volcanoes are located in a volcanic arc on the continental side of subduction zones.

28. ANSWERS
1. Composite 2. Shield 3. Cinder Cone 4. Shield 5. Composite 6. Shield 7. Cinder Cone 8. Shield 9. Composite