The Plumbing of Old Faithful

Sean Mitchell

Oct 13 | 2 min read

Photo credit: Unsplash - Andrew Sterling

Old Faithful is one of the park's most popular attractionis, tourists from all over the world travel to the park to see this famous geyser. The park may have gorgeous scenery and an abundant wildlife, but geysers such as Old Faithful is what makes Yellowstone so unique. Old Faithful is one of the 500 geysers within the park, but it is also one of the most unique geysers in the park. Just like it's name implies, it is very consistent on how often it will erupt: roughly every 90 minutes or 20 times a day. These eruptions average to 130-140 feet in height and last about 1.5 to 5 minutes in duration. Each eruption blasts our 3,700 to 8,400 gallons of scalding hot water measured at 204°F. The steam temperature measures at 350°F, enough to cook meat.

Photo credit: Unsplash - Emily Campbell

Photo credit: Unsplash - Jeffrey Hamilton

Photo credit: Unsplash - Will Myers

Generally it is pretty difficult to predict when a geyser will erupt, but Old Faithful lives up to it's name and goes off on a regular timer. The reason being is that there is a complex plumbing system underneath the geyser, the diagram below illustrates this. This plumbing system consists off many 'pipes' and resovoirs that fill up with rain water that is absorbed through the Earth's surface. Below these resovoirs are hot rocks that are heated up by the massive magma chamber beneath the park. Those hot rocks then heat up the rainwater resovoirs for about 90 minutes, slowly building up steam and pressure within the system. Eventually, the system depressurizes and erupts, causing the incredibly eruption that Old Faithful is known for.

The plumbing under Old Faithful