Abundances of Uranium and Thorium Elements in Earth Estimated by Geoneutrino Spectroscopy
Name
Geophysical Research Letters - 2022 - Abe - Abundances of Uranium and Thorium Elements in Earth Estimated by Geoneutrino.pdf
Description
Published version
Size
1.42 MB
Format
Adobe PDF
Checksum (MD5)
cfae3a263c88e15118935553131062f9
Date Issued
August 11, 2022
Journal
Geophysical Research Letters
Publisher
American Geophysical Union
Citation
Abe, S., Asami, S., Eizuka, M., Futagi, S., Gando, A., Gando, Y., et al. (2022). Abundances of uranium and thorium elements in Earth estimated by geoneutrino spectroscopy. Geophysical Research Letters, 49, e2022GL099566.
Version
Final published version
Abstract
The decay of the primordial isotopes 238U, 235U, 232Th, and 40K has contributed to the terrestrial heat budget throughout the Earth's history. Hence, the individual abundance of those isotopes are key parameters in reconstructing contemporary Earth models. The geoneutrinos produced by the radioactive decays of uranium and thorium have been observed with the Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND). Those measurements have been improved with more than 18-year observation time, and improvement in detector background levels mainly with an 8-year nearly reactor-free period, which now permit spectroscopy with geoneutrinos. Our results yield the first constraint on both uranium and thorium heat contributions. The KamLAND result is consistent with geochemical estimations based on elemental abundances of chondritic meteorites and mantle peridotites. The High-Q model is disfavored at 99.76% C.L. and a fully radiogenic model is excluded at 5.2σ assuming a homogeneous heat producing element distribution in the mantle.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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Creative Commons Attribution-NonCommercial-NoDerivatives
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DOI of Published Version
10.1029/2022gl099566