John Larson, age l4, of Virginia, Minn., for his question:

What makes hot springs hot?

The steamy water bubbles up from buried layers of lava. Hot springs occur in regionss of recent volcanic activity. The molten lava may have oozed between deep layers of granite or other rock below the surface. It may have streamed or flooded over the surface and become smothered under avalanches of solid rocks. In any case, the molten mixture is buried.

Had it remained on the surface, it soon would have lost its heat in the air and become cool. But its heat is trapped with it below the ground and it remains hot.

Ground water seeps and dribbles through the rocks, and some of it gets trapped in pockets among the hot, buried layers.  These rocks heat the water and the water comes bubbling forth as a hot spring.