Science 9: Earth and Space

Volcanoes that have erupted within the last 600 years are classified as

• inactive volcanoes.

• potentially active volcanoes.

• active volcanoes.

• dormant volcanoes.

A volcano characterized by broad, gently sloping sides formed by fluid lava flows is known as a

• cinder cone.

• composite volcano.

• shield volcano.

• lava dome.

Geothermal energy is defined as

• Energy produced by the Sun.

• Energy harnessed from Earth’s interior heat.

• Energy generated by wind turbines.

• Energy derived from ocean tides.

A tall, conical volcano built by alternating layers of lava and ash is most characteristic of a

• shield volcano.

• composite volcano.

• cinder cone.

• caldera.

In geothermal power generation, the steam produced from geothermal reservoirs is primarily used to

• provide direct heating for buildings.

• enhance agricultural irrigation.

• warm residential water supplies.

• rotate turbines connected to generators.

One theory for volcanic eruptions asserts that the buoyancy and pressure of dissolved gases within Earth cause eruptions. This theory implies that

• eruptions occur only when magma cools.

• dissolved gases expand and force magma upward.

• eruptions are triggered by tectonic plate movements.

• magma must mix with water to erupt.

According to another eruption theory, as pressure increases in magma the solubility of dissolved gases

• decreases, leading to gas bubble formation.

• remains constant.

• increases until a maximum is reached, after which the magma disintegrates.

• causes the magma to cool.

A volcano with no recorded eruptions but with a sharp, steep-sided profile is most likely

• potentially active.

• inactive.

• active.

• dormant.

Which volcano type is characterized by low-viscosity lava flows that create broad, gently sloping profiles?

• composite volcano.

• cinder cone.

• shield volcano.

• lava dome.

A small, steep, conical hill formed from volcanic debris surrounding a vent is best classified as a

• shield volcano.

• composite volcano.

• caldera.

• cinder cone.