1980 eruption of Mount St. Helens

High school (ages 12+)
Environment & Earth

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Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/1980-eruption-of-mount-st--helens

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. How tall is 1980 eruption of Mount St. Helens?80,000 feet (24 kilometers or 15 miles) above sea level
2. What is the volcanic explosivity index (VEI)?5. Indicative of a very large eruption with significant ash dispersal
3. What is the lahar reach?Extended approximately 50 miles (80 kilometers) southwest to the Columbia River
4. What happened at Mount St. Helens on May 18, 1980?A 5.1‑magnitude earthquake made the mountain’s north side collapse, sending a huge landslide that broke open the magma chamber. The hot, gas‑rich rock then exploded sideways in a powerful blast.
5. How fast did the landslide from Mount St. Helens travel?The landslide moved at speeds up to about 150 miles per hour, making it the fastest landslide ever recorded.

Phreatomagmatic Eruption: An eruption involving the interaction of magma with external water, leading to explosive steam generation.
Subaerial Landslide: A landslide that occurs on land, as opposed to underwater.
Decompression Melting: The melting of rock due to a decrease in pressure, often occurring as magma rises towards the surface.
Ecological Succession: The process by which the community of plants and animals in an area changes over time after a disturbance.