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Science in Paradise: Paradise Postponed

In 1995, people living on the tiny, green island of Montserrat woke up to the early stages of what would become devastation -- the long-dormant Soufriere Hills Volcano began sending out steam and ash, eventually burying much of the lush island in ash from deadly pyroclastic flows. Meet volcanologists who risk their lives as they keep a watch on the volcano.

Curriculum Links
National Science Education Standards
Related Frontiers Shows and Activities
Activity: Build a Mini-Volcano



plate tectonics, volcanoes


acid-base reactions


Caribbean geography


5-8: Properties and Changes of Properties in Matter, Chemical Reactions
5-8: Structure of the Earth System, Earth's History
9-12 Energy in the Earth System
Understandings about Science and Technology
5-8: Natural Hazards, Risks and Benefits
9-12: Natural and Human-induced Hazards, Science and Technology in Local, National and Global Challenges



When Scientific American Frontiers filmed this story early in 1998, most inhabitants had been evacuated from Montserrat. Those who remain on the island must live in an exclusion zone at the northern end. In July 1998, a few months after the story was filmed, Soufriere Hills erupted again. The dome seen on the show collapsed, sending toxic gases and hot ash into the atmosphere and down the mountain. Pyroclastic flows added to the new delta being created in the sea.

Many islands in the Caribbean are volcanic in origin; the region sits on top of an unstable subduction zone. You can't replicate an erupting volcano, but you can have fun making a chemical reaction with this model. And your job as volcano-watcher will be a lot safer than those you see on Frontiers!


  • baking soda
  • distilled white or regular vinegar
  • modeling clay or Play-Doh
  • plastic plate or Masonite for base
  • Alka-Seltzer and red food coloring (optional)

  1. Sculpt a mountain of clay about 9 cm high, using Masonite or other material for a base. Shape the mountain into a sloping volcano. (Make your mountain a different size, if you wish.)

  2. If needed, let the clay harden. If you're using a soft modeling clay, it does not need to dry.

  3. Scoop out about 1/3 of the top of the clay mountain to make a deep crater or hollowed-out section.

  4. Place baking soda at the bottom of the hollowed-out cone.

  5. When you are ready to watch your volcano 'erupt,' pour in a small amount of vinegar. Stand back and observe!
picture of volcano NOTE: Experiment with the amounts of baking soda and vinegar used. Start with a small amount of baking soda (about 1 teaspoon) and vinegar (about 1/4 cup) and experiment with the ratio. The 'lava' will bubble up and overflow; when it stops flowing, add more baking soda and vinegar to keep it going.

Options: Add red food coloring to the baking soda before pouring in vinegar. Drop in part or all of a crushed Alka-Seltzer tablet for special effects. The chemicals in the tablet will keep the reaction bubbling longer.


  1. Mixing baking soda (bicarbonate of soda) and vinegar creates a simple chemical reaction between an alkali or base (baking soda) and an acid. The chemical name for baking soda is sodium hydrogen carbonate; the chemical name for undiluted vinegar is ethanoic acid. What happens when a carbonate like baking soda is mixed with an acid? Carbonates contain carbon and oxygen. When the carbonate is mixed with an acid, the carbon and oxygen escape as carbon dioxide gas -- the same gas you exhale when you breathe out. Ask a chemistry teacher to help you work out the formula for this reaction. What other combinations of acids and bases could make a similar reaction?

  2. Our planet experiences many natural disasters -- volcanoes, earthquakes, tornadoes, hurricanes, floods. More and more people build their homes in areas where natural disasters have happened. Would you? What are the trade-offs?

  3. Math Extension: If the pyroclastic flow is moving at 100 mph, how far will it travel in four minutes? At 200 mph?

  4. In the summer of 1998, we saw how disasters like forest fires or a tsunami can devastate a region. If you live near a natural disaster or other major hazard, create a disaster plan for the inhabitants.

  5. Read updates of the South Soufriere Hills Volcano at:

  6. Two other famous stratovolcanoes that caused extreme destruction were Mt. Vesuvius, which erupted in A.D. 79 and destroyed the towns of Pompeii and Herculaneum, and Mount St. Helens, which erupted in Washington State in 1980. Like the Montserrat volcano, these volcanoes produce pyroclastic flows, a mixture of hot gas, rocks and ash that destroys all in its path. Gases in Earth's magma escape so forcefully that they blast hot rock into billions of particles (ash). To see pictures of active and extinct volcanoes, go to Volcano World at:


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.