Mini Lesson

Evolution of an Island

Mini Lesson

We often think of changes in land formation as events that occur over very long time scales. This is a real-life example of the formation and changes to an island over a very short geologic time scale.

Introduction to the Volcanic Phenomenon

  1. Watch the A New Time-lapse of an Island Forming in Tonga video of a newly formed island of Hunga Tonga-Hunga Ha-apai.
  2. Make observations of this volcano as it changes over time.  How does it change?  Where does it change?
  3. Think about the following questions.
    1. What did the scientists originally think would happen to the island of Hunga Tonga-Hunga Ha'apai? 
    2. What did they actually find? 
    3. What was the effect of the water on the newly formed island? 

Expand Your Understanding

Now view the The Birth of a New Island video about the formation of the island Hunga Tonga-Hunga Ha'apai and why NASA is interested in studying the island. 

After the video, answer the following questions. 

  1. How did the island form? 
  2. Why is NASA interested in studying this island? 
  3. What sort of changes did you notice in the island? 
  4. How did the geosphere and hydrosphere interact in the changes of the island? 
  5. Based on what you know about erosion and deposition, what do you think about the time scale involved in these videos? Is it faster or slower than many other areas on Earth? 


    • Visualizations: NASA's Scientific Visualization Studio
    • Satellite image of the Tongan Island courtesy of Pleiades-1A ©2015 CNES Distribution Airbus DS
    • Photo of the tephra cliffs on the island is courtesy of NASA/Damien Grouille/Cecile Sabau

    Teacher Note

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