Grand Prismatic Microbial Mat
Yellowstone National Park, Wyoming, USA
The Grand Prismatic Spring microbial mat, which is a multi-layered sheet of microorganisms, surrounds the hot springs showing off its many vivid colors. The intrinsic blue center of the pool (upper right of the photo) is completely sterile due to the extreme heat. The hot spring discharges an estimated 560 US gallons (2,100 liters) of 160 °F (70 °C) water per minute.