1. Section 13-2 Review
Page #330:1-9

2. #1 Summarize the difference between mafic and felsic magma.
Mafic Magma
magnesium & iron
dark
less viscous
Felsic Magma
silica & feldspars
light
more viscous

3. #2 Explain how the composition of magma
affects the force of volcanic eruptions.
More viscous magma traps gases more easily than less viscous magma, which may lead to more explosive eruptions.

4. #3 Compare three major types of lava flows. Pahoehoe – ropy
Aa – jagged
Blocky Lava – large chunks

5. Pahoehoe

6. Aa

7. #4 Define pyroclastic material, and list three examples.
Pyroclastic material consists of fragments of rock that form during an explosive eruption.

8. Pyroclastic Material
volcanic ash/dust
volcanic bombs
lapilli

9. Volcanic Ash

10. Bomb

11. #5 Identify the three main types of volcanic cones. shield volcano
cinder cones
composite volcano

12. Types of Volcanoes

13. Shield Volcano
Mauna Loa - Hawaii

14. Cinder Cone

15. Composite Volcano

16. #6 Describe how calderas form.
A caldera forms when the magma chamber of a volcano empties, causing the volcanic cone to collapse in upon it, or when magma is ejected violently and the cone is destroyed.

17. Caldera

18. Crater Lake

19. #7 List three events that may precede a volcanic eruption.
earthquake activity
rock temperatures increase
volcano area bulges

20. #8 Would quiet eruptions or explosive
eruptions be more likely to increase the
steepness of a volcanic cone? Explain
your answer.
Explosive eruption are more likely to increase volcano height, because the pyroclastic materials rise upward and fall close to the volcanic vent.

21. #9 Why would a sudden increase of earthquake activity around a volcano
indicate a possible eruption.
Sudden earthquake activity could be caused by magma moving upward through the rock around the volcano.

22. The End
On “Io” a moon of Jupiter