Grand Geyser is a fountain

geyser A geyser (, ) is a spring with an intermittent water discharge ejected turbulently and accompanied by steam. The formation of geysers is fairly rare and is caused by particular hydrogeological conditions that exist only in a few places on Ea ...

in the Upper Geyser Basin of

Yellowstone National Park Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. It is the tallest predictable geyser known. It was named by

Ferdinand Vandeveer Hayden Ferdinand Vandeveer Hayden (September 7, 1829 – December 22, 1887) was an American geologist noted for his pioneering surveying expeditions of the Rocky Mountains in the late 19th century. He was also a physician who served with the Union A ...

in 1871.

Eruptions

Grand's fountain reaches a height of as much as , with a duration of 9 to 12 minutes. Its eruptions occur in a series of 1 to 4 (rarely as many as 5) bursts.

Sequence

Grand erupts every 4 to 8 hours. It belongs to the Grand Group (or Grand Geyser Complex), and its eruption is connected to those of the other geysers in the group, especially the adjacent Vent Geyser and Turban Geyser. For a few hours before an eruption by Grand, Turban Geyser erupts for a duration of five minutes about every 17 to 22 minutes. Grand's eruption begins within 1 to 2 minutes of the start of one of Turban's eruptions, it can also erupt just before Turban's eruption begins, with Vent Geyser erupting shortly after Grand starts erupting. On occasion, Grand will stop erupting after 7 to 9 minutes, only to restart with a usually taller fountain a minute or two later. Grand has been known to rarely experience over half a dozen restarts in a single eruption period. After Grand ceases its eruption, Vent and Turban can continue to erupt for another hour. As of 2018, Grand Geyser has become extremely predictable, with nearly every eruption being 6–7 hours apart. Upon the finish of an eruption, Grand's pool is empty and takes about five hours to refill.

References

External links

* {{Wyoming Geysers of Wyoming Geothermal features of Teton County, Wyoming Geothermal features of Yellowstone National Park Geysers of Teton County, Wyoming