1. Volcanoes
Quiet
lava
flows

2. Volcano locations

3. What is a volcano?
• Volcano- Areas of earth’s surface through
which magma and volcanic gases pass
• Volcano comes from the Roman word Vulcan,
which means “fire”

4. What’s inside a volcano?
• Magma Chamber-
molten rock that
feeds a volcano
• Vents- cracks in
the crust
• What is the
difference
between magma
and lava?

5. Volcanoes
Mt. St. Helen before the explosive eruption

6. Volcanoes

7. Volcanoes
Time lapse of the eruption

8. Volcanoes
Mt. St. Helen after the eruption

9. Volcanoes

10. Volcanoes

11. Eruptions and volcanic material
GASES
vent
PYROCLASTIC
MATERIALS
volcanic
cone
LAVA
pipe
(conduit)
magma
chamber

12. Materials released in volcanic eruptions
PYROCLASTIC MATERIAL
carbon
dioxde
ash water
vapour
sulphur
lapilli gases
carbon
monoxide
volcanic
bombs
GASES

13. Materials released in volcanic eruptions
PYROCLASTIC MATERIAL
carbon
dioxde
ash water
vapour
sulphur
lapilli gases
carbon
monoxide
volcanic
bombs
GASES

14. Types of eruptions
HAWAIIAN STROMBOLIAN VULCANIAN

15. Types of eruptions
Shield volcano
magma chamber central vent
pipe (conduit)
• magma temperature: very high (over 1,000 ºC)
• very liquid lava
HAWAIIAN • not very destructive nor explosive
STROMBOLIAN VULCANIAN

16. Types of Volcanoes
• Shield Volcano
a) Built from layers of
lava
b) Non-explosive
eruptions
c) Not very steep, but
can be big

17. Types of eruptions
Stratovolcano (composite volcano)
central volcanic cone
vent
magma chamber pipe (conduit)
• magma temperature: moderate (700 - 1,000 ºC)
• thick lava
STROMBOLIAN
HAWAIIAN STROMBOLIAN VULCANIAN
• explosive pyroclastic material

18. Types of Volcanoes
• Composite Volcanoes
a) Most common type
b) Explosive eruptions
and lava flow
c) Built from pyroclastic
material AND lava

19. Types of eruptions
Dome volcano
volcanic pipe of
magma chamber solidified lava
• magma temperature: low (less than 700 ºC)
VULCANIAN
HAWAIIAN • violent,STROMBOLIAN
destructive explosions VULCANIAN
• generally gases and ash are expelled

20. Types of Volcanoes
• Cinder Cone or dome
Volcano
a) Built from pyroclastic
material
b) Moderately explosive,
short eruptions
c) Small in size, steep
slopes