Types Of Volcanoes

Question 1

Name the 6 types of volcanoes

Answer 1

• Lava plateaux
• Shield
• Acid/dome
• Cinder cone
• Composite cone/stratovolcanoes
• Calderas

Question 2

Give the characteristics, formation and an example of lava plateaux volcanoes

Answer 2

• Characteristics: Flat and featureless
• Formation: Fissure eruptions with runny basaltic lava travelling large distance
• Example: Antrim lava plateaux, N. Ireland

Question 3

Give the characteristics, formation and an example of shield volcanoes

Answer 3

• Characteristics: Gentle sides covering large area
• Formation: Basaltic lava travels significant distance, built up by accretion of thousand of lava flows
• Example: Mauna Loa, Hawaii

Question 4

Give the characteristics, formation and an example of acid/dome volcanoes

Answer 4

• Characteristics: Steep sided convex cones
• Formation: Viscous rhyloitic lava, cooling quickly forming steep sides
• Example: Mount Vesuvius

Question 5

Give the characteristics, formation and an example of cinder cone volcanoes

Answer 5

• Characteristics: Steep and relatively symmetrical
• Formation: Layers of ash, cinders and volcanic bombs ejected from single vent, form a cone
• Example: Paricutin, Mexico

Question 6

Give the characteristics, formation and an example of composite/stratovolcanoes

Answer 6

• Characteristics: Classic pyramid shape, layers of ash and lava
• Formation: Viscous andesitic lava cools quickly. Lava solidified within fissures act as ‘ribs’ strengthening cone
• Example: Mount Etna, Sicily

Question 7

Give the characteristics, formation and an example of calderas

Answer 7

• Characteristics: Huge craters from violent eruptions, may be flooded by sea forming lake
• Formation: Build up of gases becomes extreme and explosion removes top of cone leaving large opening
• Example: Krakatoa, Indonesia

Question 8

Outline the order of highest silicon levels, to lowest silicon levels within lava types

Answer 8

1) Rhyolitic
2) Andesitic
3) Basaltic

Question 9

What does increasing silicon content cause?

Answer 9

More viscous and less runny lava

Question 10

Name the two types of eruptions

Answer 10

• Explosive

- Effusive

Question 11

Outline explosive eruptions

Answer 11

• Andesitic and rhyolitic lava form silica rich, viscous magma
• Solidifies before reaching surface, causing build up of pressure and violent eruptions

Question 12

Outline effusive eruptions

Answer 12

• Basaltic lava form magma low in silica

- Fluid magma that allows gas bubbles to expand on way to surface, preventing sudden explosive activity