Partial radiogenic heat model for Earth revealed by geoneutrino measurements


Journal Article

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± 1.0TW, 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. © 2011 Macmillan Publishers Limited. All rights reserved.

Full Text

Duke Authors

Cited Authors

  • Gando, A; Gando, Y; Ichimura, K; Ikeda, H; Inoue, K; Kibe, Y; Kishimoto, Y; Koga, M; Minekawa, Y; Mitsui, T; Morikawa, T; Nagai, N; Nakajima, K; Nakamura, K; Narita, K; Shimizu, I; Shimizu, Y; Shirai, J; Suekane, F; Suzuki, A; Takahashi, H; Takahashi, N; Takemoto, Y; Tamae, K; Watanabe, H; Xu, BD; Yabumoto, H; Yoshida, H; Yoshida, S; Enomoto, S; Kozlov, A; Murayama, H; Grant, C; Keefer, G; Piepke, A; Banks, TI; Bloxham, T; Detwiler, JA; Freedman, SJ; Fujikawa, BK; Han, K; Kadel, R; O'Donnell, T; Steiner, HM; Dwyer, DA; McKeown, RD; Zhang, C; Berger, BE; Lane, CE; Maricic, J; Miletic, T; Batygov, M; Learned, JG; Matsuno, S; Sakai, M; Horton-Smith, GA; Downum, KE; Gratta, G; Tolich, K; Efremenko, Y; Perevozchikov, O; Karwowski, HJ; Markoff, DM; Tornow, W; Heeger, KM; Decowski, MP

Published Date

  • September 1, 2011

Published In

Volume / Issue

  • 4 / 9

Start / End Page

  • 647 - 651

Electronic International Standard Serial Number (EISSN)

  • 1752-0908

International Standard Serial Number (ISSN)

  • 1752-0894

Digital Object Identifier (DOI)

  • 10.1038/ngeo1205

Citation Source

  • Scopus