Grand Prismatic Spring: Bacteria causes amazing colours in America's largest hot spring

The Grand Prismatic Spring is also the third largest in the world.

The Grand Prismatic Spring's multicoloured water is one of nature's most breathtaking spectacles.

Located in Yellowstone National Park, in Wyoming, United States, the hot spring is known worldwide for its extremely hot water and stunning prismatic colours.

Discovered by geologists in 1871, it is the largest hot spring in America and the third largest in the world. It has a diameter of about 295 feet and a depth of 164 feet.

Curiously, the colourful spectrum that attracts visitors from around the world is the result of pigmented thermophiles bacteria that inhabit the water around the edges of the spring.

The colours produced by the bacteria are determined by the temperature and depend on the ratio of chlorophyll to carotenoids present in the water.

In the center of the spring the water is so hot that the bacteria is not able to survive, whereas the temperature gradually drops towards the edges. This explains why the dazzling bright yellows, fierce oranges and deep reds only appear around the edges while the deep blue remains confined to the centre.