thermo-, therm-, thermi-, -thermia, -therm, -thermal, -thermic, -thermias, -thermies, -thermous, -thermy

(Greek: heat, heating, heater, hot, warm)

The term heat is employed in ordinary language in different senses. Some scientists distinguish four principal applications of the term:

  1. Sensation of heat.
  2. Temperature, or degree of hotness.
  3. Quantity of thermal energy.
  4. Radiant heat, or energy of radiation.

A temperature-time curve of the amount of heat produced in a chemical reaction.
1. Denoting a chemical reaction during which heat is emitted.
2. Relating to the external warmth of the body.
3. A compound that liberates heat during its formation and which absorbs heat or energy during its decomposition.
4. Characterized by, or attended by, the development of heat; such as, combustion.
Relating to or describing any process in which a system releases heat to its surrounding environment.
geoisotherm (s) (noun), geoisotherms (pl)
An underground isotherm, or a line drawn on a weather map that connects places with the same temperature: A geoisotherm is a long thin mark connecting points of equal or constant temperatures on the surface of the Earth.
geological thermometer, geologic thermometer (s) (noun); geological thermometers; geologic thermometers (pl)
The presence of a mineral or an aggregate of minerals defines the temperature ranges or limits of the minerals which had been formed: A geological thermometer can measure the temperatures in boreholes in order to provide information about the temperature range within which minerals had been formed.
geothermal (adjective) (not comparable)
Relating to, or caused by, the internal heat of the Earth: Mr. Thompson's house was warmed up by geothermal energy.

While at the hot springs, Jill let her feet dangle in the water and enjoyed the geothermal warmth it provided.

geothermal agriculture (s) (noun), geothermal agricultures (pl)
The use of geothermic heat in farming: Geothermal agriculture is the use of low-temperature geothermal water to warm irrigation water or to sterilize soil.
geothermal aquaculture (s) (noun), geothermal aquacultures (pl)
The use of geothermal heat in fish farming: Geothermal aquaculture is used to warm up the water in order to provide a controlled environment for the husbandry of marine organisms.
geothermal cooling (s) (noun) (no pl)
The use of naturally-cooler water, or air, to lower the temperature of a building, as opposed to air or water that is artificially cooled: Those who utilize heat pumps in a system of geothermal cooling save up to 70% on heating expenses in addition to 50% on cooling costs.
geothermal drilling (s) (noun), geothermal drillings (pl)
The process of drilling a well to explore for or to extract geothermal energy, or to re-inject thermal waste water in the ground after power generation: Geothermal drilling entails boring a hole deep into the ground and pumping water back up. The method of geothermal drilling is a fantastic way of heating one's home.

You may see more information about geothermal drilling here.

geothermal energy, geothermal heat, geothermal heating (s) (noun) (no pl)
1. Energy in the form of natural heat flowing outward from within the plant Earth and contained in rocks, water, brines, or steam: Geothermal heat is produced mainly by the decay of naturally occurring radioactive isotopes of thorium, potassium, and uranium in the Earth's core.

Geothermal energy is produced by tapping the Earth's internal heat. At present, the only available technologies to do this are those that extract heat from hydrothermal convection systems, where water or steam transfer the heat from the deeper part of the Earth to the areas where the energy can be tapped.

The amount of pollutants found in geothermal vary from area to area but may contain arsenic, boron, selenium, lead, cadmium, and fluorides. They also may contain hydrogen sulphide, mercury, ammonia, radon, carbon dioxide, and methane.

Getting the Earth's Heat

Geothermal power plants, which tap hot subterranean water or steam, are high on the lists of at least thirty states in the U.S. which are requiring utility companies to generate some portion of their electricity from such renewable sources.

Most utilities have not pursued geothermal energy primarily because up-front costs, including exploratory drilling, can be expensive since geothermal taps deep reservoirs, not groundwater, which collects much closer to the surface.

An extensive study recently released by the Massachusetts Institute of Technology has shown that the heat available under ground is surprisingly plentiful nationwide.

—This segment of information came from
"Heating Up" by Mark Fishetti; Scientific American,
October, 2007; page 80.

A page about geothermal energy in Iceland. More information about special Geothermal Energy sources.

geothermal gradient (s) (noun), geothermal gradients (pl)
The rate of temperature change in soil and rock from the surface to the interior of the Earth: The geothermal gradient on the average is estimated to be an increase of about +10°C per kilometer.

Quiz You can find self-scoring quizzes over many of the words in this subject area by going to this Thermo- Vocabulary Quizzes page.

Related "heat, hot" word units: ferv-; pyreto-.

Related "bubble" word unit: ebulli-.