Hot spring

A hot spring is a spring produced by the emergence of geothermally heated groundwater from the Earth's crust. Hot springs are in many places, especially in mountains. The water issuing from a hot spring is heated by geothermal energy, i.e., heat from the Earth's mantle.

Grand Prismatic Spring and Midway Geyser Basin in Yellowstone National Park

Guelma in Algeria

Hot spring in Lassen Volcanic National Park

Definitions

"Blood Pond" hot spring in Beppu, Japan

There is no universally accepted definition of a hot spring. For example, one can find the phrase hot spring defined as

• any geothermal spring ^[1]
• a spring with water temperatures above its surroundings ^[2][3]
• a spring with water temperatures above 50 °C (122 °F) ^[4]
• a natural spring with water temperature above body temperature – normally between 36.5 and 37.5 °C (97.7 and 99.5 °F) ^{[5][6][7][8][9]}
• a natural spring of water greater than 21.1 °C (70 °F) (synonymous with thermal spring) ^{[10][11][12][13]}
• a natural discharge of groundwater with elevated temperatures ^[14]

Related pages

• Geyser
• Hydrothermal vent