Awards, Grants, and Contests

Olivia Harris

Award: Top 100

School: trinity school
Teacher: mark schober
Category: Natural
Photo #19625

The Physics of a Chromatic Hot Spring

During a family trip to Yellowstone National Park we encountered this hot spring,  one of many incredible geothermal features in the park,  and it is a wonderful example of physics in action. The geysers and hot springs of Yellowstone exist because the area sits above a geothermal hot spot,  where molten rock or magma in Earth's crust generates an enormous amount of heat and some volcanic activity. Earth's interior is unusually hot. In a hot spring like this one,  underground water is heated by the nearby hot rocks and magma. As the water heats up,  it becomes less dense and rises,  while cooler water at the surface sinks and is then heated in turn. This continuous movement forms a convection cycle. Additionally,  the mist above the spring is created by the temperature difference between the hot water and the cooler surrounding air. I took this photo on a warm day,  so the mist was thinner
than it would have been on a colder day,  when a greater temperature contrast would create more mist. The vibrant blue colors in the water result from microorganisms that thrive in hot temperatures called thermophiles. Different microorganisms live in different temperatures throughout the hot spring,  creating the gradient of color. This hot spring also beautifully illustrates geothermal energy in action,  as its heat source comes directly from deep within the Earth.