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Active, Dormant, or Extinct?

Science · Volcanoes & Earthquakes · ages 7-9

Name ______________________ Date ____________

Which label means scientists do not expect another eruption?
- Active
- Dormant
- Extinct
A volcano is erupting now. Which label fits in this lesson?
- Active
- Dormant
- Extinct
A dormant volcano is quiet now, but it could erupt again someday.
Circle one: True False
A dormant volcano has been quiet for 100 years. Why do scientists still watch it?
- Its quiet years prove an eruption will happen next week.
- Its quiet years prove that no eruption can happen again.
- Another eruption is possible after a long quiet time.
A volcano has been quiet for 250 years. Scientists think it could erupt again. Which label fits this lesson?
- Active
- Dormant
- Extinct
A volcano has been quiet for 50 years. That fact alone proves it is extinct.
Circle one: True False
A volcano erupted 10 years ago and is called active. Does that label mean another eruption will happen soon?
- Yes. Active means an eruption will happen in the next few days.
- Yes. All active volcanoes erupt again after the same wait.
- No. Active does not give a date for another eruption.
Scientists called a volcano extinct. New evidence suggests it could erupt again. What should they do?
- Keep the old label because it can never change.
- Review the label using the new evidence.
- Set the label using only the years since it last erupted.

Answer key

For grown-ups. Fold this page away before handing over the rest.

Extinct · Extinct is the label used when scientists do not expect another eruption.
Active · A volcano erupting now is active. Dormant describes a long quiet period, and extinct means another eruption is not expected.
True · Dormant means quiet for a long time while another eruption is still possible.
Another eruption is possible after a long quiet time. · A dormant volcano may erupt again. Watching for changes helps scientists judge possible danger, but quiet years do not prove safety or set an eruption date.
Dormant · Dormant fits the two clues: a long quiet period and the possibility of another eruption. The number of years alone would not settle the label.
False · Quiet years alone do not prove extinction. Scientists need other evidence about whether another eruption is possible.
No. Active does not give a date for another eruption. · An active label does not mean an eruption will happen soon. The past eruption date does not give the date of the next one.
Review the label using the new evidence. · The new evidence challenges the earlier assessment. Scientists should review the label using that evidence.