Artemisia Geyser is a geyser

Geyser

A geyser is a spring characterized by intermittent discharge of water ejected turbulently and accompanied by a vapour phase . The word geyser comes from Geysir, the name of an erupting spring at Haukadalur, Iceland; that name, in turn, comes from the Icelandic verb geysa, "to gush", the verb...

 in the Upper Geyser Basin of Yellowstone National Park

Yellowstone National Park

Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

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Geology

Artemisia Geyser is part of the Cascade Group which includes the Atomizer Geyser

Atomizer Geyser

Atomizer Geyser is a cone geyser in the Upper Geyser Basin of Yellowstone National Park in the United States. Atomizer Geyser is part of the Old Road Group which includes Artemisia Geyser, a short distance down the Firehole River from Old Faithful and other major Upper Basin geysers...

. It erupts for a duration of 15 to 25 minutes once or twice per day. The fountain reaches a height of 30 feet (9.1 m). Artemisia's pool overflows quietly for many hours before an eruption, but gives no visible warning of an impending eruption until the sudden increase in overflow that marks the eruption's onset. Eruptions are accompanied by a strong underground thumping caused by steam bubbles collapsing in the geyser's channels.

Artemisia also experiences minor eruptions lasting about 5 minutes. These minor eruptions are followed by major eruptions within six hours. Minor eruptions are rare. Years may pass between episodes of minor eruptions.

In 2009, intervals between eruptions ranged from 9 to 36 hours, averaging 18 hours, 43 minutes.