What's Happening Underground?
Taking the Soil's Temperature!

— Digging Deeper—

  • Pursuing Questions : Go back to the list of questions the class developed during the activity. Ask, Which questions could we answer through more observations? Which could we answer by setting up an experiment? Which can we answer through research or asking experts? Follow up and try to find answers.

  • Underground Winter Survival: Remind students that frogs, worms and countless other creatures survive the winter by living underground. Have students choose one such animal and then do research to learn about the adaptations it has in order to survive the winter underground.

  • Underground Temperature Graphs: If you have older students, show them large versions of one or both of the graphs below. Ask these types of questions: What statement(s) can you make after looking at the graph? What does it tell you about soil (and air) temperatures? (During the summer? During the winter?) How would you explain what you see?

    A. Soil temperatures over three days at different depths. (Click for a larger image.)

    • At shallow depths, soil temperatures fluctuate a great deal.
    • The deeper you go in the soil, the more constant the temperatures.

    B. Soil temperatures during a year at different depths. (Click for a larger image.)

    • In the winter, the deeper the soil, the warmer the temperature. This reverses in the summer.
    • In general, deeper the soil, the more constant the temperatures.