There are many thermal pools steaming away in Yellowstone National Park. a favorite of mine (and many others) being the Morning Glory Pool. Situated about a mile and a half from Old Faithful, this is a beautiful 20 foot deep spring whose waters are amazingly clear and whose colors are vibrant! The water is a very vivid bluish-green and the bacterial mats at the edges of the pool add interesting contrasts of yellow, orange and brown. Rarely, mostly after an earthquake, the pool can erupt as a geyser.
Pools such as this are among the rarest geologic formations on the planet. Besides venting the heat of subterranean magma, here only a few miles (six or so) below the surface, they are home to some of the rarest and most interesting bacteria on the planet. These bacterial mats contain thermophils (heat loving bacteria) that are adapted to live in water that is almost at its boiling point. These bacteria have proven extremely important in DNA technology, such as the “DNA fingerprint” analysis we’re used to seeing on CSI type crime shows.
Sadly, Morning Glory Pool has been altered by careless human activity. Over the years stupid people have tossed in coins, rocks, wood and even trash. Periodically the park needs to clean it out, which it does with a large vacuum hose. This crap people throw in has plugged up some of the pool’s vents, and water doesn’t circulate as quickly any more. This has resulted in a subtle cooling of the water and an increased growth of the bacterial mat towards the pool’s center.
I was lucky enough to have a polarizing filter on my lens, or we’d have seen little of the pool’s vivid colors — just clouds reflected off its surface. But the images give you a hint of the amazing colors of this place.