Physical Geography

Earth Science

Volcano Case Study: Mount St. Helens, U.S.A

Mt. St.Helens Eruption 1980

In May 1980 Mount St.Helens, an active volcano in the Cascade Range of mountains in the western USA, erupted with unexpected violence after over 100 years of inactivity.

The eruption was unique because the mountain had been carefully monitored by scientists during the months before the eruption, and sensitive measuring equipment was still in place when the eruption started.

Measurements and even video footage of the eruption were recorded, making it one of the best recorded eruptions available to scientists. The wealth of data, the magnitude of the eruption and the devastation it caused, make it an excellent Case Study of an erupting composite volcano.

Print out and read the article about Mount St. Helens, then answer the following questions.

1. What name is used to describe scientists who study volcanoes?
2. Mount St.Helens is part of the Cascade Range of mountains. How did this range of mountains form, and how does its formation explain the presence of active volcanoes such as Mt. St.Helens?
3. In your own words write a short account of the clues available to the scientists that suggested an eruption might occur.
4. The eruption began in the morning of 18th May 1980. Read carefully through the account of the eruption and produce a diary of the events that happened between 8:30 am on 18th May and 5th June the same year. List all the events mentioned in the account, and add any other information you can discover from other sources such as books and internet sites.
5. How and why did the mountain's covering of snow and ice contribute to the extent of the disaster?
6. From what you have read, and discovered from other sources, explain how the eruption effected the lives, both social and business, of the communities around the volcano. What short term and long term effects did the eruption have on the human population?
7. Why do you think that people choose to live in areas close to mountains such as Mt St.Helens, when they know that there could be volcanic eruptions?