Exit78 Photo of the Day #100
Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, August 6, 2010 (Pentax K10D)
Grand Prismatic Spring (Wikipedia)
The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States, and the third largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. It is located in the Midway Geyser Basin.
Grand Prismatic Spring was noted by geologists working in the Hayden Geological Survey of 1871, and named by them for its striking coloration. Its colors match the rainbow dispersion of white light by an optical prism: red, orange, yellow, green, and blue.
The vivid colors in the spring are the result of microbial mats around the edges of the mineral-rich water. The mats produce colors ranging from green to red; the amount of color in the microbial mats depends on the ratio of chlorophyll to carotenoids and on the temperature gradient in the runoff. In the summer, the mats tend to be orange and red, whereas in the winter the mats are usually dark green. The center of the pool is sterile due to extreme heat.
The deep blue color of the water in the center of the pool results from the intrinsic blue color of water. The effect is strongest in the center of the spring, because of its sterility and depth.
The spring is approximately 370 feet (110 m) in diameter and is 160 feet (50 m) deep. The spring discharges an estimated 560 US gallons (2,100 L) of 160 °F (70 °C) water per minute.
Series notes:
- The photos in this series are (usually) randomly selected from a batch of photos specifically “curated” for Exit78 Photo of the Day.
- Each photo in this series is an “original work” – a copyright term – of Michael Goad.
