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 analysis highlights hydrothermal systems formed by meteor impacts as an overlooked but potentially important setting for life's beginnings.

From Science Daily • Apr. 3, 2026

The scientists examined genetic material collected from volcanic lakes in Iceland and from deep-sea hydrothermal vents located more than two kilometers beneath the North Atlantic Ocean.

From Science Daily • Mar. 14, 2026

Broz noted that kaolinite can also form through hydrothermal processes on Earth, where hot water alters rock underground.

From Science Daily • Jan. 27, 2026

Data from three separate sites were used to evaluate whether hydrothermal activity could explain the Martian samples, and the results favored rainfall as the most likely cause.

From Science Daily • Jan. 27, 2026

A number of experiments to determine this hydrothermal equivalent have been made and the results are recorded beyond, together with a discussion of the nature of the experiments.

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