Opal Pool is a

hot spring A hot spring, hydrothermal spring, or geothermal spring is a Spring (hydrology), spring produced by the emergence of Geothermal activity, geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow ...

in the Midway 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 ...

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

. Opal Pool usually has a temperature of approximately . Though usually active as a hot spring, Opal Pool is considered a fountain-type geyser. The first recorded eruption of Opal Pool was in 1947, recurring in 1949, 1952 and 1953, then ceasing. Eruptions resumed in 1979, happening at least once in most following years. Eruption heights are typically under in height, but some eruptions have been seen with heights of to . Eruptions occur suddenly following visible convection in the pool, but are unpredictable. An eruption consists of one huge burst that throws water 20–80 feet high, making Opal Pool the largest active geyser at Midway Geyser Basin. Much smaller splashes seconds apart stretch the total duration to about 1 minute. In 2005 Opal completely drained, but refilled as a vivid green pool in 2008.

References

Geysers of Wyoming Geothermal features of Teton County, Wyoming Geothermal features of Yellowstone National Park Geysers of Teton County, Wyoming {{wyoming-geo-stub

See also

References