1. When Volcanoes Erupt PG. 107

2. Volcano
a break/hole on the crust of Earth that emits lava, ash, and gases. (usually forms a mountain)

3. What’s inside a volcano?
Crater The central funnel shaped vent at the top of a volcano
Vent—an opening at the surface of the Earth through which volcanic material passes
Magma Chamber—the body of molten rock that feeds a volcano
Magma Chamber

4. What are non- explosive eruptions?
Volcanoes that erupt only lava and gas
The most common type of eruption

5. What erupts from a volcano?
1. Lava-- 4 types
Pahoehoe
Low viscosity- flows quickly, smooth glassy surface
A’a—high viscosity- flows slowly, brittle jagged surface

6. Pillow lava—lava that erupts under water
Blocky lava—sharp edged chunks of stiff lava

7. What are explosive eruptions?
Clouds of hot rock, ash and gas rapidly shoot out from the volcano
Millions of tons blast out in a few seconds

8. 2. Pyroclastic material 4 types of material
Bombs—large blobs of magma that harden when they fly through the air
Blocks—largest pieces of solid rock blown away from the volcano

9. 4. Volcanic ash– magma explodes into tiny glass like slivers
3. Lapilli—little stones of magma that harden before they hit the ground

10. What are pyroclastic flows?
Enormous amounts of hot ash, dust and gas are ejected from a volcano
Races downhill at more than 200 km / hr
Temperatures can exceed 700 degrees C

11. What are the effects of volcanic eruptions?
Climate can be changed as ash and gas spread throughout the atmosphere
Eruptions can affect the whole Earth with lower temperatures

12. Other effects… Pyroclastic materials (ash and rock)
can travel at high speeds and can be deadly
Lava can be very destructive—it’s very hard to stop

13. Mt. Vesuvius and Pompeii

14. Mt. Vesuvius and Pompeii

16. 3 types What are other types of Volcanic Landforms?
1. Lava Lakes- large amounts of molten lava contained in a depression A

17. 2. Calderas
A semicircular depression that forms when the magma chamber partly empties and causes the ground above to sink
Many times larger than a crater

18. 3. Lava Plateaus
A wide flat area caused by repeated nonexplosive eruptions of lava that spread over a large area