Why do Volcanoes Erupt?

What influences the explosivity of a volcano's eruption according to the text?

• The size of the volcano

• The shape of the volcano

• How "sticky" or "fizzy" the magma is

• The amount of water in the crater or caldera

What analogy is used in the text to illustrate the concept of magma's viscosity?

• Pouring water from a bottle

• Blowing bubbles in cooking oil versus jam or peanut butter

• Breaking volcanic ash with fingers

• Lava flowing down a volcano

What is lava?

• Magma that is found inside the Earth

• Magma that has reached the surface

• The frothy, bubbly magma inside a volcano

• The hard pieces called tectonic plates

What is the danger of explosive volcanic eruptions as described in the text?

• They can form new islands

• They can cause earthquakes

• They can produce volcanic ash that is dangerous to breathe

• They can create new mountains

According to the text, what can result if airplanes travel through an ash cloud from a volcano?

• The flights can be expedited due to the tailwind

• The passengers can encounter turbulence

• The scenery can be enhanced for passengers

• It can inflict damage to the airplane engines

What is one of the benefits of volcanoes mentioned in the text?

• They provide a habitat for unique wildlife.

• Volcanic ash enriches the soil around volcanoes.

• They create new landforms in the ocean.

• They are a major tourist attraction.

How is the heat from some volcanoes utilized according to the text?

• To warm homes during winter.

• To prepare food for local communities.

• To generate energy to power lights, fridges, televisions, and computers in people's houses.

• To establish hot springs for recreational purposes.

What is the author's main purpose for writing this selection?

• To describe the beauty and power of volcanoes

• To warn readers of the dangers of volcanoes

• To compare how volcanoes are formed

• To explain what causes volcanoes to erupt