hydrothermal

American  

[hahy-druh-thur-muhl] / ˌhaɪ drəˈθɜr məl /

adjective

Geology.

1. noting or pertaining to the action of hot, aqueous solutions or gases within or on the surface of the earth.

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hydrothermal British  

/ ˌhaɪdrəʊˈθɜːməl /

adjective

1. of or relating to the action of water under conditions of high temperature, esp in forming rocks and minerals

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hydrothermal Scientific  

/ hī′drə-thûr′məl /

1. Relating to or produced by hot water, especially water heated underground by the Earth's internal heat.

2. ◆ Hydrothermal energy is power that is generated using the Earth's hot water.

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Other Word Forms

• hydrothermally
  adverb

Etymology

Origin of hydrothermal

First recorded in 1840–50; hydro- ¹ + thermal

Explanation

The adjective hydrothermal is used to describe hot water, particularly water that's heated underground. If you visit Yellowstone, you'll probably see hydrothermal attractions like geysers and hot springs. Hydrothermal derives from Greek roots hydor, "water," and therme, "heat." It's been used by geologists since the 1850s to describe underground hot water. Hydrothermal activity occurs all over the planet, and it's especially common around active volcanoes. As well as steamy hot springs and dramatic geysers shooting hot water into the air, smaller mud pots and hydrothermal vents in the ocean floor are also evidence of water heating up beneath the earth's surface.

Example Sentences

Her initial task was to explore whether hydrothermal vents on Mars could have supported life.

From Science Daily • Apr. 3, 2026

"And now you get a hydrothermal vent system, just like in the deep sea, but made by the heat from an impact."

From Science Daily • Apr. 3, 2026

With this discovery, Milos stands out as one of the most important natural sites in the Mediterranean for exploring how tectonics, volcanism, and hydrothermal processes interact beneath the sea.

From Science Daily • Dec. 30, 2025

A new study published in Scientific Reports describes the discovery of an unusually large hydrothermal vent field on the shallow seafloor surrounding the Greek island of Milos.

From Science Daily • Dec. 30, 2025

Such corrections are impossible unless a proper determination of the hydrothermal equivalent has been made.

From Respiration Calorimeters for Studying the Respiratory Exchange and Energy Transformations of Man by Benedict, Francis Gano