8.2 Volcanic Eruptions

What is Mount St. Helens known for in US history?

• Largest earthquake

• Deadliest and costliest volcanic eruption

• Tallest mountain

• Longest river

What makes each volcanic eruption unique?

• The size of the volcano

• The chemical composition of the magma

• The height of the volcano

• The age of the volcano

What does the chemical composition of magma influence in a volcano?

• The color of the lava

• The eruption style, type of cone, and rock composition

• The speed of the lava flow

• The temperature of the lava

What happens if felsic magma rises into a magma chamber?

• It may become too viscous to move

• It flows rapidly to the surface

• It cools and solidifies immediately

• It turns into a gas

What happens to felsic magma that stays deeper in the crust?

• It cools to form igneous intrusive rocks

• It erupts violently

• It evaporates

• It turns into sedimentary rock

What is the primary component of the erupted material in an explosive eruption?

• Water

• Tephra

• Sand

• Gravel

What is the primary reason for the explosive nature of felsic magmas?

• Low temperature

• High gas content

• High density

• Low viscosity

How high did the cloud reach above Mt. Redoubt?

• 30,000 feet

• 35,000 feet

• 40,000 feet

• 45,000 feet

Which eruption was the most recent Cascades eruption before Mount St. Helens in 1980?

• Mount Rainier

• Mount Hood

• Lassen Peak

• Mount Adams

What natural event caused disruption to air travel across Europe in April 2010?

• Earthquake

• Hurricane

• Volcanic eruption

• Tsunami