Grand Geyser is a fountain

geyser A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...

in the

Upper Geyser Basin The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10, ...

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowston ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. 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 Ar ...

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 Vent Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Vent Geyser belongs to the Grand Group (or Grand Geyser Complex), and its eruption is tied to Grand Geyser Grand Geyser is a fountain geyser ...

and

Turban Geyser Turban Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Turban Geyser belongs to the Grand Group (or Grand Geyser Complex), and its eruption is tied to Grand Geyser. In the hours prior to Grand's er ...

. 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