Exploring History's Most Destructive Volcanoes

What was the magnitude of the earthquake that triggered the 1980 eruption of Mount St. Helens?

• 6.0

• 7.2

• 5.1

• 4.5

What is the name of the area of devastation caused by the 1980 eruption?

• The Blast Zone

• The Pyroclastic Zone

• The Lava Zone

• The Ash Zone

Which animal was one of the first signs of life returning to Mount St. Helens after the eruption?

• Northern Pocket Gopher

• Prairie Dog

• Field Mouse

• Ground Squirrel

What plant species was found flourishing on the pumice plain, aiding in the ecological recovery?

• Alpine Aster

• Prairie Lupine

• Dandelion

• Mountain Laurel

What unusual geological feature formed during the 2004 eruptions of Mount St. Helens?

• Lava Fountains

• Lava Tubes

• Lava Spines

• Lava Lakes

What term did scientists use to describe the repetitive seismic signals associated with the lava spines?

• Heartbeat

• Echoes

• Drumbeats

• Pulses

What is the main factor that determines whether a volcanic eruption will be explosive or effusive?

• Temperature of the magma

• Amount of gas in the magma

• Type of rock in the magma

• Depth of the magma chamber

How long do scientists estimate it takes for Mount St. Helens to build up enough gas for a major eruption?

• 2,000 years

• 1,000 years

• 3,000 years

• 500 years

What geological feature allows scientists to study the history of Mount St. Helens' eruptions?

• Seismic Records

• Ash Layers

• Crater Walls

• Lava Tubes

What is the main challenge scientists face in predicting the next eruption of Mount St. Helens?

• Measuring the temperature of the magma

• Determining the exact gas content

• Understanding the seismic activity

• Finding a reliable indicator of eruption timing