The Science Behind the Colors of Yellowstone

Yellowstone National Park is an undoubted national treasure, best known for its stunning display of vivid color. With an inside of bright blue that matches the sky and an outside comparable to a raging fire, Yellowstone is a site of unmatched visual quality. But just what causes this incredible display?

The Bacteria Behind the Beauty

Surprisingly, living organisms are actually what cause the bright colorations at Yellowstone. More specifically, there are several species of bacteria that can only survive in specific temperatures and acid levels. Each of the colorful rings is home to a unique species of bacteria at the park.

But why the rings of color?

All organisms can only survive in certain environments. While one may be able to survive extreme cold, another may be able to withstand life deep, deep underwater. Yet another may thrive in a very hot environment. The bacteria in Yellowstone are accustomed to the heat of the water, but at varying levels of comfort.

In the center of the spring the water is at its most warm. At roughly 189 degrees Fahrenheit, few organisms can survive, even bacteria. Thus the water in the center of the spring is deep blue; it is just pure water.

As the water spreads towards the sides, it cools, creating several unique environments for several species of bacteria.

Blue fades into green, and eventually yellow. In the green and yellow band you’ll find the cyanobacteria Synechococcus, which can survive in the cooler 165 degrees Farenheit water only through its use of photosynthetic pigments that help to reduce the damaging effect of the harsh sun in the area. And its these pigments give off the green and yellow colors.

Orange and Red

In the orange and red rings some new bacteria come into play.

As LiveScience explains:

In the orange band, which is a cooler 149 degrees F (65 degrees C), you’d find not only Synechococcus bacteria but also Chloroflexus bacteria, which also contain both chlorophyll, for photosynthesis, and the carrot-colored carotenoids. Two other bacteria that produce orange-colored mats, Phormidium and Oscillatoria, which are both found in Mammoth hot springs within Yellowstone.

At the outermost area you’ll see a deep red-brown. This is the “coolest” part of the spring, though it is still extremely warm for most life to live at 131 degrees. However, there is a great diversity of microbes in this part of the spring, and one such bacteria, Deinococcus Thermus Thermus, produces the distinct brown.

It is quite spectacular that living organisms can create this stunning visual. Celebrating 100 years, the National Parks Service has a true gem in Yellowstone National Park.

For a more comprehensive list of the bacteria that contribute to the colors in Yellowstone National Park, explore the resources below.

Resources for Educators:

• The Smithsonian explains Yellowstone National Park
• LiveScience article
• American Geophysical Union article