Volcanoes

Question 1

Volcanism

Answer 1

Molten magma rises within the Earth and is erupted either quietly as lava, or violently as pyroclastic

Question 2

Volcanic Controls

Answer 2

• Controls of explosivity:
  1. Silica content
  2. Gas content of the magma
  Magmas with higher silica are more viscous

Question 3

Basalt Volcano

Answer 3

50% SiO2, gas-poor

Question 4

Andesite Volcano

Answer 4

60% SiO2, gas-rich

Question 5

Rhyolite Volcano

Answer 5

70% SiO2, gas-rich

Question 6

Volcano Distribution

Answer 6

Most are located in the Pacific Ring of Fire, on plate boundaries