geothermometer

From geo- +‎ thermometer.

geothermometer (plural geothermometers)

1. (geology) A proxy that allows for geothermometry, the determination of the temperature of a geological material from the past or existing at great depth.
   • 1966, Zheng Xilai, Liu Hongjun, “STUDY OF THE WATER-ROCK EQUILIBRIUM STATE IN THE APPLICATION OF GEOTHERMOMETER”, in Journal of Xi'An Engineering, volume 1:

     The geothermometer is often used to calculate the deep temperatures of geothermal reservoirs on the basis of water-rock equilibrium in the exploration of geothermal resources.

   • 1986 January, B.W. Robinson, D.S. Sheppard, “A chemical and isotopic study of the Tokaanu-Waihi geothermal area, New Zealand”, in Journal of volcanology and geothermal research, volume 27, numbers 1-2:

     The sulphate-water geothermometer indicates that the deep hot water is at 250°C.

   • 1979 December, Wook Han, “A Preliminary Evaluation of Geothermal Potential of Korea with Emphasis on Geothermometer and Mixing Model”, in The Journal of the Geological Society of Korea, volume 15, number 4:

     The Na-K-Ca geothermometer and silica geothermometer are discussed as tools for locating and evaluating the areas prospectively valuable for geothermal development.

2. (obsolete) A thermometer designed for measuring extremely high temperatures below ground level.
   • 1880 July, “The Interior of the Earth”, in Popular Science, volume 17, number 19:

     Walferdin's registering thermometer and the geothermometer of Magnus are constructed on this principle.

   • 1881, Hermann Joseph Klein, Land, sea and sky; or, Wonders of life and nature, page 291:

     It is most important to notice that the experiment at Sperenberg shews that there is no regular, uninterrupted increase of temperature corresponding to the increase of depth, but that the increase of heat occurs more slowly at very great depths; in other words, that the degrees of the geothermometer grow longer as it descends.

   • 1896, Oliver Lanard Fassig, Report - Volume 3, page 697:

     In England about this time the problem of constructing maximum and minimum thermometers was actively taken up. Lord Charles Cavendish first solved this question in 1757, and later in a similar way Magnus, in Berlin, for the geothermometer, and Walferdin, in Paris, by the metastatischen thermometer.”

   • 1902, Institution of Civil Engineers (Great Britain), Minutes of Proceedings of the Institution of Civil Engineers, page 402:

     For the determination of the geothermal gradient, that is, the depths that must be reached in order to find increments of 1° C. in the temperature, the geothermometer is employed.

• geothermometric
• geothermometry

• “geothermometer”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.