1. Chapter 5: Lesson 3:
How do
volcanoes
shape the
land?

2. Openings in earth’s crust.

3. Volcanoes are located on certain places on
earth’s surface.
(Found where tectonic plates meet)

4. A circle of volcanoes (Ring of fire) follows the
boundaries of plates that meet along the pacific
ocean.

5. Eruption
Outpouring of ash, gases, lava or a combination of these.

6. Inside a volcano
Smoke and ashes
Crater
Vent
Lava
Vent
Magma chamber

7. Crater
(cup shaped
depression)

8. Volcanoes erupt where one plate is pushed
under another.

9. Caldera
The hole that is formed when the chamber
under the volcano is emptied and the volcano
collapses.

10. Underground magma formations
1) Dike
(Formed when magma hardens in vertical or nearly
vertical cracks)

11. 2) Sill
(Formed when magma hardens in horizontal layers of
rock)

12. 3) Laccolith
(A dome shape formed when magma is pushed into a sill
and doesn’t spread)
When a laccolith is formed it may push the layers of rock above it.

13. 4) Batholith
(Huge, irregular shape deep in the earth’s crust)

14. Types of volcanoes
Active volcanoes
Dormant Extinct volcanoes
volcanoes
(Currently erupting or
(Stopped
recently erupted)
(Does not erupt
erupting)
for some time)
Shield
volcanoes
Cinder- Composite
cone
volcanoes
volcanoes

15. 1) Shield volcanoes
Built by thinner, fluid lava that spreads over a
large area.
(Broad base and gently sloping sides)

16. 2) Cinder-cone volcanoes
Formed by thick lava that is thrown high up in the
air and fall as chunks or cinders.
(Form as cone shape with narrow base and steep sides)

17. 3) Composite volcanoes
Built by layers of ash and cinders sandwiched
between layers of hardened lava.
(Both sides of a composite volcano look the same)

18. Active volcano not on
boundary

19. Hot spot
(A stationary pool of magma)
The Hawaiian islands are
form an island chain.
The origin of the
Hawaiian island
volcanoes is the hot
spot.

21. Island arc
(Formed in areas where an ocean floor
plate is pushed under another ocean floor
plate.)