Volcanoes

In which location would you MOST LIKELY find volcanoes?

• far from plate boundaries

• along transform boundaries

• where two continental plates collide

• along mid-ocean ridges and where a plate is subducted

Before lava reaches the surface, the molten material is called

• rock

• magma

• volcanic ash

• liquid fire

The main factor that accounts for the difference between quiet and explosive volcanic eruptions is

• the size of the volcano's magma chamber

• the iron content of the magma

• the age of the volcano

• the silica content of the magma

The main hazard from a quiet volcanic eruption is

• volcanic gases

• lava flows

• geysers

• pyroclastic flows

What provides the force that causes magma to erupt to the surface?

• the silica in the magma

• dissolved gases trapped in the magma

• gravity in the lithosphere

• the density of the magma

If geologists detect many small earthquakes in the area near a volcano, what can they infer about the volcano?

• It is dormant.

• It is probably about to erupt.

• It is extinct.

• It is a good source of geothermal energy.

Tall, cone-shaped mountains in which layers of lava alternate with layers of ash are called

• shield volcanoes

• cinder cone volcanoes

• composite volcanoes

• lava plateaus

When many layers of thin, runny lava build up a high, level area, the result is a

• lava plateau

• shield volcano

• cinder cone volcano

• composite volcano

The huge hole left by the collapse of a volcanic mountain is called a

• lava plateau

• caldera

• cinder cone

• shield volcano

When magma hardens in a volcano's pipe, the result will eventually be a landform called a

• batholith

• dike

• volcanic neck

• sill