Volcanoes Test Review

What is a volcano?

• A type of rock
• A landform formed around a volcanic opening
• A type of gas
• A type of mineral

Where does magma form?

• In the Earth's atmosphere
• Deep within the Earth
• In the ocean
• On the Earth's surface

What are the three conditions required for magma formation?

• Increase in pressure, decrease in temperature, increase in water
• Decrease in pressure, increase in temperature, increase in water
• Increase in pressure, increase in temperature, decrease in water
• Decrease in pressure, decrease in temperature, increase in water

Where are most volcanoes formed?

• At subduction boundaries
• At divergent boundaries
• At hot spots
• At continental boundaries

How does magma rise to the surface?

• It becomes denser than the surrounding material
• It becomes less dense than the surrounding material
• It evaporates and turns into gas
• It remains at the same depth

What happens when an oceanic plate subducts beneath a continental plate at a subduction boundary?

• Volcanoes form on the subducting plate
• Volcanoes form on the overriding plate
• Volcanoes form on both plates
• No volcanoes form

What causes large amounts of magma to form at divergent boundaries?

• Increase in pressure and decrease in temperature
• Decrease in pressure and increase in temperature
• Increase in pressure and increase in temperature
• Decrease in pressure and decrease in temperature

What are hot spots?

• Areas of volcanic activity at plate boundaries
• Areas of volcanic activity caused by human activity
• Areas of volcanic activity caused by earthquakes
• Areas of volcanic activity caused by rising plumes of hot material from the Earth's mantle

How do hot spots remain in the same place even as lithospheric plates move across them?

• They move with the plates
• They are anchored to the Earth's core
• They are unaffected by plate movement
• They are deeper than the plates

What determines the viscosity of magma?

• Silica
• Water vapor
• Carbon dioxide
• Basaltic rock