The Upper Geyser Basin, Y.N.P.

Yellowstone is most known for its wildlife, endless backcountry, and hydrothermal features. The upper geyser basin, where Old Faithful is located, is one of three locations on the earth with a large concentration of hydrothermal activity. Magma is somewhere from 3 to 8 miles below the surface of Yellowstone and provides the heat necessary to create hydrothermal activity. When rain water and melted snow seep through the cracks of the earth, it gets low enough to be heated by the magma. Steam and pressure is created under the earth and something gives to release the pressure. The pressure is released in many forms. Hot springs have water that rises to the surface and either pours off the side or is cooled enough to return back below. Fumaroles are steam vents which constantly vent sauna-hot air. Mudpots have just enough water to form mud and the heat is released via the boiling mud. Finally, the most famous of the features, geysers have pressure build below the surface and once the pressure gets too great, a violent explosion of hot water and steam are vented. These explosions can be minutes to hours long.

There are two types of geysers, cone-type and fountain-type geysers. Cone-type geysers send a constant jet of water out when they erupt. Fountain-type geysers gush a bunch of water in numerous spurts and in various directions.

In Yellowstone, Old Faithful is the most famous of all the geysers.

It erupts an average of once every 92 minutes and lasts from 2 to 5 minutes in duration. It spurts water into the air anywhere from 106 to 184 feet. Its consistency is due to its plumbing system not being closely linked with any other hydro-thermal features. Its consistent performance and spectacular height, neither a common trait, have earned it deserved fame.

Although many will just stay long enough to see an Old Faithful eruption, there are many other thermal features in the upper geyser basin. The closest geyser to Old Faithful that I have seen go off is Lion Geyser, part of the Lion Group geysers. The Lion group consists of 4 geysers: Little Cub, Lioness, Big Cub, and Lion. Lion is a cone-type geyser with a large cone. It erupts approximately 80 feet in the air for 1-7 minutes. It showed off to me during sunset.

The park rangers predict eruption times for 5 geysers in the upper geyser basin. They are Old Faithful, Castle, Grand, Daisy, and Riverside. Castle erupts about every 13 hours to a height of 75 feet. The prediction time is typically plus or minus 2 hours so it can be a time consuming process to wait for it. The geyser is named for the sinter cone it has made over thousands of years of eruptions.

Grand geyser is the second most popular geyser in the upper geyser basin. It is the tallest predictable geyser in the world with eruptions up to 200 feet. Grand is very different from Old Faithful in that it is a fountain geyser. Water is shot out in spurts. This is Grand geyser when it is dormant.

This is Grand geyser when it is active.

Riverside geyser is next to the firehole river and provides unique scenery for a geyser eruption. It’s eruption is much longer than Grand or Old Faithful, lasting approximately 20 minutes. Riverside erupts once every 6 hours at heights up to 75 feet. It is a fountain-type geyser. Note the boiling hot water next to the river on the left hand side of the photo, that’s a dormant riverside geyser.

This is an active riverside geyser.

These are the only geysers we have captured on camera. Hopefully, this blog entry can be updated with shots of an active Castle geyser or Daisy geyser.

Although geysers attract the most people, many of the hot springs around the upper geyser basin provide incredible color and beauty. My personal favorite is Chromatic Pool.

Note the amazing number of colors in the hot springs. The colors are due to thermophiles, heat-loving algae, bacteria, and archaea. Lots of research is being put into understanding thermophiles and how they survive incredible temperatures. NASA is a primary sponsor of the research, so they can understand how to search for life elsewhere in our universe. The colors also help represent the temperature of the water at certain points. The sapphire blue is the hottest region. The orange-red is the cooler region. Sorry, but I can’t recall the temperature ranges.

Gem Pool has classic hot spring shape and color.

Sapphire pool is a large pool with incredible color. It erupted in 1959 blowing away numerous “biscuits” that had surrounded the pool.

To view all of these thermal features and many more, it was a comfortable 2.5 miles walk. Truly an amazing place on planet earth.