October 28, 2016:
Geysers and mudpots and hot springs, oh my!
Yellowstone is probably best known for its hydrothermal features. We aren’t going to give you a tour of the various basins and sites and the various features they contain, but more of an overall view of what the features are like. You really need to go and see for yourself.
The best known hydrothermal feature in Yellowstone is, of course, Old Faithful. It not only puts on an impressive show, sending a plume of super heated water as high as 185 feet (56 m), it is also one of the most predictable geysers on Earth, erupting about every hour. It’s been doing that since explorers discovered and named it in 1870. [click to enlarge]
Old Faithful is just one of many hundreds of geysers in Yellowstone. It’s not even the biggest, just the best known and most reliable.
Many are a lot less reliable.
The park’s, and probably the world’s highest currently active geyser is Steamboat Geyser (above), which can erupt up to 300 feet (91 m) into the air. It might not be worth waiting around to see it, though. It hasn’t erupted in more than 2 years, and the period between major eruptions has varied between 4 days and 50 years.
Most geysers are a lot smaller. [click to enlarge]
It was fun to watch this one drain and fill:
Some erupt pretty much all the time:
Yellowstone is home to hundreds of clear and colorful hot spring pools. [click to enlarge]
These springs may be boiling hot, or they may appear to boil as gasses from far below bubble up to the surface.
Some of these springs look like they would be a great place to take a dip, especially on a chilly fall day. In reality, many of these pools are either so hot or so acidic (or both) that the park takes serious measures to ensure that you can view them, but stay out of them.
These measures include boardwalks through hydrothermal viewing areas [click to enlarge]:
Some folks don’t have the good sense to heed the repeated signed warnings and decide to venture off the boardwalks. Disaster can ensue.
There’s a lot of color around many of the hydrothermal features. [click to enlarge]
What causes those brilliant colors? For the most part it’s caused by thermophilic (heat loving) microbes. Microbes of different colors have their own preferred temperatures, resulting in colored patterns as the water changes temperature.
The minerals and microbes in these pools join up to form interesting new structures. [click to enlarge]
On a larger scale, silica and other minerals dissolved into the water below get left behind, creating a new stony mineral, geyserite: [click to enlarge]
In some places, there is relatively little water, and more minerals. In these places, features range from tinted water to slowly bubbling mud pots:
Some of these features become more or less viscous as the seasons become wetter or drier.
In addition to geysers and mudpots and hot springs, there are also several places where steam escapes from underground through vents called fumaroles. Sometimes just a gentle mist, and sometimes blasting out like an industrial nightmare.
Many of these features are accompanied by a strong odor of sulfur, and some, particularly the fumaroles, make foreboding hissing and roaring noises. It certainly isn’t surprising that some explorers and early (possibly present) visitors have wondered if they were witnessing the gateway to the underworld.
The hydrothermal features constantly shift. Today’s parking lot is tomorrow’s steam vent:
One of the best parts about walking around and seeing all these hundreds of features is that there is so much variety. Each feature is the result of a unique collection of water temperature, water quantity, soil conditions, and other factors, so that most really are something quite new to look at. And on top of that, you’re looking at all these amazing features in the context of an otherwise amazing place:
We think Yellowstone would be one of the amazing places on Earth, just because of its hydrothermal features. But stay tuned, we have another side of Yellowstone to show you. In the meantime, here are some more pictures: