Mount St. Helens Eruption Insights

Where is Mount St. Helens located?

• Oregon

• California

• Washington State

• Idaho

What were some of the warning signs that Mount St. Helens was about to erupt in 1980?

• Increased seismic activity and steam venting

• Changes in the mountain's color and shape

• Unusual animal migration patterns

• Sudden drops in temperature

When did Mount St. Helens have its spectacular and deadly eruption?

• May 18, 1990

• May 18, 1980

• April 22, 1980

• June 1, 1990

What was the immediate impact of the Mount St. Helens eruption on the surrounding forest?

• It caused a massive wildfire.

• It leveled the forest up to 13 miles from the volcano.

• It created new lakes and rivers.

• It covered the forest in a thick layer of ice.

What was the temperature and speed of the pyroclastic flow that raced down the valley during the eruption?

• 1000 degrees Fahrenheit at 200 mph

• 1800 degrees Fahrenheit at 450 mph

• 500 degrees Fahrenheit at 100 mph

• 2000 degrees Fahrenheit at 600 mph

What was the first type of plant to return to the Mount St. Helens area after the eruption?

• Pine trees

• Alpine lupine

• Oak trees

• Ferns

How did the first plants to return to Mount St. Helens contribute to the ecosystem's recovery?

• They provided immediate food for large mammals.

• They created soil from the volcanic ash.

• They absorbed all the remaining toxic gases.

• They prevented further volcanic activity.

What prevents Sitka willows from growing large enough to provide habitat for birds and mammals in the recovering ecosystem?

• Lack of sunlight

• Competition from other plant species

• Damage from weevils

• Insufficient water supply