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Old Faithful

earth science Maturity 7-9 Next article →

Old Faithful is a famous cone geyser. It sits in Yellowstone National Park in Wyoming. This geyser is very special because it is predictable. Most geysers are hard to time. You might wait a long time for one. Old Faithful erupts on average every 92 minutes.

This reliability makes it a wonderful thing to see. It is part of the Old Faithful Historic District. The nearby Old Faithful Inn is also in this area.

How does this geyser work? It shoots boiling water into the air. An eruption can last from 1.5 to 5 minutes. Scientists used probes to look deep inside the ground. They lowered tools as deep as 150 feet.

Old Faithful eruptions graph
Old Faithful eruptions graph

These probes showed how water fills the underground pipes. They also saw superheated steam entering the conduit. The conduit is the path the water takes. They even saw fog form from mixing air temperatures.

People discovered this geyser a long time ago. The Washburn-Langford-Doane Expedition found it in 1870. They traveled down the Firehole River. They saw it after passing the Kepler Cascades.

It was the first geyser in the park to get a name. Nathaniel P. Langford wrote about it in 1871. In the early days, people even used it for laundry. More than 1,000,000 eruptions have been recorded by people.

There are many interesting facts about its timing. The wait between eruptions depends on the last one. If an eruption lasts less than 2.5 minutes, it waits about 65 minutes. If it lasts longer than 2.5 minutes, it waits about 91 minutes.

Old Faithful eruptions graph
Old Faithful eruptions graph

Earthquakes can change these patterns. A Borah Peak earthquake in 1983 changed the intervals. It made the waits between eruptions longer. Harry Woodward found a math pattern for this in 1938.

Old Faithful is not the biggest geyser around. Steamboat Geyser is the largest in Yellowstone. It is also less predictable than Old Faithful.

Old Faithful eruptions graph
Old Faithful eruptions graph

You can think of Old Faithful like a steady clock. It follows a pattern that most people can rely on. It stays predictable because it is not connected to other hot features. This makes it a unique part of the Upper Geyser Basin. It is a true wonder of the natural world.

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