Questions for ‘As Yellowstone’s supervolcano slumbers, another big danger lurks’ 

a clear pool of water with crystals at the edges is steaming as the sun sets

The area around West Thumb Geyser Basin and Yellowstone Lake has been rocked in the past by many hydrothermal explosions. They’re powered by the same heat from underground magma that feeds the park’s famous hot springs and geysers.

Siraphob Tatiyarat/Moment/Getty Images

To accompany As Yellowstone’s supervolcano slumbers, another big danger lurks’  

SCIENCE

Before Reading:

  1. Consider the word hydrothermal. This word starts with a prefix: hydro. Think about where you have heard this prefix and in what context. What do you think this prefix means? The word hydrothermal ends with a suffix: thermal. What might this suffix mean? To the best of your knowledge, piece together the meaning of hydrothermal based on this information.
  2. A pressure cooker is a household appliance that cooks food quickly in a pressurized container. A small amount of water must be added to the pressure cooker to work properly. Then, the lid is sealed, and the water is heated into steam. Based on this information, explain the source of the “pressure.” Be sure to explain the role of water in this pressurization process. Modern pressure cookers have many safety devices, such as valves that open if the pressure becomes too high. Why do you think it’s vital for these appliances to have such safety features?

During Reading:

  1. How many years ago did Yellowstone’s volcano last erupt?
  2. What was the first sign of trouble observed by visitors to Japan’s Mount Ontake on September 27, 2014?
  3. How did water contribute to the Mount Ontake disaster?
  4. What is a phreatic explosion?
  5. What is the source of the “sour” smell in Yellowstone National Park’s Pocket Basin?
  6. During a 1966 visit to Yellowstone National Park, Donald White noticed something that led him to conclude that Pocket Basin was a huge crater left over from a past hydrothermal explosion. What observation led to this realization?
  7. What “change at the surface” did scientists conclude resulted in this explosion?
  8. What is the diameter of Elliot’s crater in meters?
  9. According to core sample data, how many thousands of years ago did Elliot’s crater form?
  10. How does Lauren Harrison expect the drier weather caused by climate change to affect the frequency of hydrothermal explosions in Yellowstone?

After Reading:

  1. Scientists in this story used “core samples” for clues into the geological history of Elliot’s crater. Scientists obtain a core sample by drilling a tube deep into the lake floor and drawing out a long cylindrical sample. How might scientists use such samples to figure out what has happened in the past? How do you think scientists determine the age of different parts of the sample?
  2. Scientists in this story are working to unlock secrets of Yellowstone National Park’s geological history. How might answers to such questions help people in the future? Give a specific example of how this information might be used to help people.