Imaggeo on Mondays: Grand Prismatic Spring

Yellowstone National Park, USA, is well known for its outstanding natural beauty.

“Grand Prismatic Spring” by David Mencin, distributed by the EGU under a Creative Commons licence.

This is the Grand Prismatic Spring in the Midway Geyser Basin, Yellowstone National Park. It is the third largest hotspring in the world and the largest found in the United States, with a maximum diameter of about 90 m. It discharges roughly 2.5 cubic metres of mineral-rich water per minute, which flows down the rocky terraces evenly on all sides. Hotsprings are rich in minerals because warmer water is capable of holding more dissolved solids than colder water – and the water here can reach 87 °C in the centre of the spring!

Little can survive these high temperatures, though there are strains of thermophyllic (heat loving) bacteria and algae (chemoautotrophs and heteroautotrophs) that thrive in these conditions! There is more life found at the edges of the spring where waters are cooler. Rather than producing energy from the sun, as is the case for photosynthetic bacteria, chemoautotrophic bacteria oxidise minerals in the spring-water to produce energy. Heteroautotrpohs, on the other hand, use both photosynthesis and chemoautotrophy to obtain their energy.

These bacteria are also responsible for the bright rings of colour that surround the spring. Coating the rock in large bacterial mats; their energy-harnessing pigments dictate the colours that surround the water. If the bacteria contain more chlorophyll, the mats will be more green in colour and if they contain more carotenoids, the bacterial carpet will be more of an orangey brown.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their images to this repository and since it is open access, these photos can be used by scientists for their presentations or publications as well as by the press and public for educational purposes and otherwise. If you submit your images to Imaggeo, you retain full rights of use, since they are licensed and distributed by the EGU under a Creative Commons licence.