Cheryl Santa Maria
If a rainbow were to come crashing from the sky, it would probably look a lot like the Grand Prismatic Spring.
Hues of red, orange and blue splatter the earth in Yellowstone National Park, in an area halfway between the Upper and Lower Geyser Basins.
Discovered by geologists in 1871, it is the third largest hot spring in the world with a diameter of 90 metres and a depth of 50 metres.
The colourful spectrum is the result of pigmented bacteria in microbial mats that form around the edges of the spring, and the amount of colour the bacteria produces depends on the ratio of chlorophyll to carotenoids present and the temperature of the water, which varies with the seasons.
"This past summer brother and I drove across the US, making stops at points of interest along the way," photographer Tim Warris told The Weather Network in 2012, when he snapped these incredible photos.