Morning Glory Pool is a hot spring

Hot spring

A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...

 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...

.

History

The pool was named by Mrs. E. N. McGowan, wife of Assistant Park Superintendent, Charles McGowan in 1883. She called it "Convolutus", the Latin name for the morning glory

Morning glory

Morning glory is a common name for over 1,000 species of flowering plants in the family Convolvulaceae, whose current taxonomy and systematics is in flux...

 flower of which the springs resemble. By 1889, the name Morning Glory Pool had become common usage in the park. Many early guidebooks called this feature Morning Glory Spring.

Composition

The distinct color of the pool is due to bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 which inhabit the water. On a few rare occasions the Morning Glory Pool has erupted as 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...

, usually following an earthquake or other nearby seismic activity.

Vandalism

Several entryways have been clogged due to objects being thrown in by tourists, reducing the hot water supply, and in turn altering the overall appearance of the pool. Several attempts by park officials to artificially induce eruptions to clear the pool of debris and clear blocked entryways have been met with mixed results. An interpretive sign, placed near the pool by the park service, discusses the damage caused by ignorance and vandalism and suggests that Morning Glory is becoming a "Faded Glory."