Mount St. Helens

Frequently Asked Questions and Answers about Mount St.Helens

Mount St. Helens is the most active volcano in the contiguous United States, which makes it a fascinating place to study and learn about. Scientists receive many questions about the volcano, and some of the most frequently asked are compiled below.

Historical Facts about Mount St.Helens

  • Where did the name "Mount St. Helens" come from?
  • What is the early-settlement documentation of Mount St. Helens?

1980 Eruption

  • How high was Mount St. Helens before the May 18, 1980 eruption. How high was it after?
  • How much ash was there from the May 18, 1980 eruption of Mount St. Helens?
  • How far did the ash from Mount St. Helens travel?
  • For additional information, read the website section dedicated to the May 18, 1980 eruption and activity from 1980-1986.

2004-2008 Eruptive Activity

  • How large is the lava dome, and how does it compare to the 1980–1986 dome?
  • What is the evidence that the lava dome stopped growing in 2008?
  • Why is this considered to be a pause? Why is the Alert Level being lowered to Advisory (Color Code Yellow) instead of Alert Level Normal (Color Code Green)?
  • If the eruption resumes, what kinds of precursors are likely to provide warning?
  • What are some of the lessons that scientists learned from the 2004-2008 eruption?
  • For additional information, read the website section dedicated to the 2004-2008 period of volcanic activity.