Volcanic Hazards

What is the term for a volcano that has not erupted for many years but may erupt again in the future? (Fill in the blank)

• dormant volcano

• sleeping volcano

• extinct volcano

• active volcano

Which type of volcano is known for its explosive eruptions and steep sides?

• A. Shield volcano

• C. Hotspot

• D. Lava dome

• B. Composite

Explain the difference between a pyroclastic flow and a lahar in relation to volcanic hazards. (Short answer)

• Pyroclastic flows are slow-moving mixtures of hot gas and volcanic materials, while lahars are fast-moving mudflows composed of volcanic materials and water.

• Pyroclastic flows are composed of water and volcanic materials, while lahars are composed of hot gas and volcanic materials.

• Pyroclastic flows are not a volcanic hazard, while lahars are the most dangerous volcanic hazard.

• Pyroclastic flows are fast-moving mixtures of hot gas and volcanic materials, while lahars are slower-moving mudflows composed of volcanic materials and water.

What is the name for the opening at the top of a volcano where lava, ash, and gases are ejected? (Fill in the blank)

• crater

• chimney

• fissure

• abyss

List three primary gases released during a volcanic eruption. (Short answer)

• Water vapor, carbon dioxide, sulfur dioxide

• Oxygen

• Methane

• Nitrogen

How does the viscosity of magma affect the type of eruption? (Short answer)

• Low viscosity magma leads to explosive eruptions.

• Viscosity of magma has no impact on the type of eruption.

• High viscosity magma leads to explosive eruptions, while low viscosity magma leads to effusive eruptions.

• High viscosity magma leads to effusive eruptions.

What is the Ring of Fire and why is it significant in terms of volcanic activity? (Short answer)

• The Ring of Fire is significant in terms of volcanic activity because it is a region with a high concentration of active volcanoes and frequent volcanic eruptions.

• The Ring of Fire is a mythical artifact that controls volcanic eruptions

• The Ring of Fire is a secret society of volcano worshippers

• The Ring of Fire is a popular amusement park with volcanic-themed rides

Describe the process of volcanic lightning during an eruption. (Short answer)

• Volcanic lightning occurs due to the presence of water in the volcanic plume.

• Volcanic lightning is a result of the volcanic eruption creating a magnetic field.

• During a volcanic eruption, volcanic lightning is generated by the collision of ash particles, rock fragments, and ice particles within the volcanic plume, creating static charges that discharge as lightning.

• Volcanic lightning is caused by the eruption of lava alone.

What is the Volcanic Explosivity Index (VEI) used for? (Short answer)

• To study ocean currents

• To predict earthquakes

• To measure the temperature of lava

• To measure the explosiveness of volcanic eruptions

What are the main factors that influence the explosivity of a volcanic eruption? (Short answer)

• Presence of nearby bodies of water, seismic activity in the region, and vegetation cover

• Distance from the equator, elevation of the volcano, and time of day

• Composition of magma, amount of dissolved gases, and magma viscosity

• Temperature of the surrounding environment, wind speed, and humidity levels