Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 2011 | Published + Supplemental Material
Journal Article Open

Partial radiogenic heat model for Earth revealed by geoneutrino measurements


The Earth has cooled since its formation, yet the decay of radiogenic isotopes, and in particular uranium, thorium and potassium, in the planet's interior provides a continuing heat source. The current total heat flux from the Earth to space is 44:2±1.0 TW, but the relative contributions from residual primordial heat and radiogenic decay remain uncertain. However, radiogenic decay can be estimated from the flux of geoneutrinos, electrically neutral particles that are emitted during radioactive decay and can pass through the Earth virtually unaffected. Here we combine precise measurements of the geoneutrino flux from the Kamioka Liquid-Scintillator Antineutrino Detector, Japan, with existing measurements from the Borexino detector, Italy.We find that decay of uranium-238 and thorium-232 together contribute 20.0^(+8.8)_(-8.6)TW to Earth's heat flux. The neutrinos emitted from the decay of potassium-40 are below the limits of detection in our experiments, but are known to contribute 4TW. Taken together, our observations indicate that heat from radioactive decay contributes about half of Earth's total heat flux. We therefore conclude that Earth's primordial heat supply has not yet been exhausted.

Additional Information

© 2011 Macmillan Publishers Limited. Received 5 November 2010; accepted 14 June 2011; published online 17 July 2011. We thank E. Ohtani and W. F. McDonough for advice and guidance. The KamLAND experiment is supported by a Grant-in-Aid for Specially Promoted Research under grant 16002002 of the Japanese Ministry of Education, Culture, Sports, Science and Technology; the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan; and the US Department of Energy (DOE) grants DEFG03-00ER41138 and DE-AC02-05CH11231, as well as other DOE grants to individual institutions. The reactor data are provided by courtesy of the following electric associations in Japan: Hokkaido, Tohoku, Tokyo, Hokuriku, Chubu, Kansai, Chugoku, Shikoku and Kyushu Electric Power Companies, Japan Atomic Power Company and Japan Atomic Energy Agency. The Kamioka Mining and Smelting Company has provided service for activities in the mine. Author contributions: All authors contributed equally to the work presented in this study.

Attached Files

Published - Gando2011p15815Nat_Geosci.pdf

Supplemental Material - ngeo1205-s1.pdf


Files (672.5 kB)
Name Size Download all
490.0 kB Preview Download
182.5 kB Preview Download

Additional details

August 22, 2023
October 24, 2023