Going East….to West-11

Thermal Features in Yellowstone National Park

One can see a variety of thermal features in Yellowstone National Park: Hot Springs, Cone/Fountain Geysers and Mud Pots/Volcanoes. It is said that the colours and shapes that inspire artists have geothermal origin. Thomas Moran (you may recall his role in Hayden Geological Survey in 1871) was greatly impressed with various tints (Yellow, Red, White and Pink) that one sees on rocks lining Yellowstone River’s Grand Canyon; he had once remarked that these “tints are beyond the reach of human art” although he did try to capture these beautiful colours on canvas while painting the Grand Canyon. These tints are caused by the chemical reaction that the minerals have on the rock. What Thomas Moran says about Grand Canyon also holds true for these thermal features and more since besides the colours mentioned above, one also sees Blue and Green probably due to greater presence of Sulphur (Sulfur). One gets a little uncomfortable with the strong odour of Sulphur while walking alongside some of these. What an element Sulphur is,—it gives heat, colour and a strong odour to anything that it comes in contact with.

Mud Pots or Volcanoes are a little different from these geysers. These can be simply described as bubbling mud and are caused by a perfect mix of heat, gases, water, volcanic rock, minerals, acid and even living microorganisms called “thermophiles”. These heat-loving microorganisms consume some of the gases and help convert them into sulphuric (sulfuric) acid. The acid breaks down rock to form clay—clay that mixes with water to form these mud pots. I read somewhere that when one sees them, one gets a feeling that one is watching a planet being born. How true indeed!

You can now see below various colours that these thermal features are dressed in.