TY - JOUR
T1 - Radiogenic Power and Geoneutrino Luminosity of the Earth and Other Terrestrial Bodies Through Time
AU - McDonough, W. F.
AU - Šrámek, O.
AU - Wipperfurth, S. A.
N1 - Funding Information:
W. F. M. gratefully acknowledges NSF support (EAR1650365), S. A. W. acknowledges support from NSF (EAPSI #1713230) and Japanese Society for the Promotion of Science (SP17054), and O. Š. acknowledges Czech Science Foundation support (GAČR 17‐01464S) for this research. We thank the many geophysics, cosmophysics, nuclear physics, and particle physics friends who have helped us to understand many of the details of these calculations, especially, Béda Roskovec, Steve Dye, John Learned, Sanshiro Enomoto, Hiroko Watanabe, Katherine Bermingham, Sarah Stewart Mukhopadhyay and Richard Ash. Review comments by Andy Davis, Thomas Ruedas, Herbert Palme, and anonymous reviewer #3 are greatly appreciated. We are grateful to Janne Blichert‐Toft for her comments and editorial efforts.
Publisher Copyright:
©2020. American Geophysical Union. All Rights Reserved.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - We report the Earth's rate of radiogenic heat production and (anti)neutrino luminosity from geologically relevant short-lived radionuclides (SLR) and long-lived radionuclides (LLR) using decay constants from the geological community, updated nuclear physics parameters, and calculations of the β spectra. We track the time evolution of the radiogenic power and luminosity of the Earth over the last 4.57 billion years, assuming an absolute abundance for the refractory elements in the silicate Earth and key volatile/refractory element ratios (e.g., Fe/Al, K/U, and Rb/Sr) to set the abundance levels for the moderately volatile elements. The relevant decays for the present-day heat production in the Earth (19.9 ± 3.0 TW) are from 40K, 87Rb, 147Sm, 232Th, 235U, and 238U. Given element concentrations in kg-element/kg-rock and density ρ in kg/m3, a simplified equation to calculate the present-day heat production in a rock is (Formula presented.). The radiogenic heating rate of Earth-like material at solar system formation was some 103 to 104 times greater than present-day values, largely due to decay of 26Al in the silicate fraction, which was the dominant radiogenic heat source for the first ∼10 Ma. Assuming instantaneous Earth formation, the upper bound on radiogenic energy supplied by the most powerful short-lived radionuclide 26Al (t1/2 = 0.7 Ma) is 5.5×1031 J, which is comparable (within a factor of a few) to the planet's gravitational binding energy.
AB - We report the Earth's rate of radiogenic heat production and (anti)neutrino luminosity from geologically relevant short-lived radionuclides (SLR) and long-lived radionuclides (LLR) using decay constants from the geological community, updated nuclear physics parameters, and calculations of the β spectra. We track the time evolution of the radiogenic power and luminosity of the Earth over the last 4.57 billion years, assuming an absolute abundance for the refractory elements in the silicate Earth and key volatile/refractory element ratios (e.g., Fe/Al, K/U, and Rb/Sr) to set the abundance levels for the moderately volatile elements. The relevant decays for the present-day heat production in the Earth (19.9 ± 3.0 TW) are from 40K, 87Rb, 147Sm, 232Th, 235U, and 238U. Given element concentrations in kg-element/kg-rock and density ρ in kg/m3, a simplified equation to calculate the present-day heat production in a rock is (Formula presented.). The radiogenic heating rate of Earth-like material at solar system formation was some 103 to 104 times greater than present-day values, largely due to decay of 26Al in the silicate fraction, which was the dominant radiogenic heat source for the first ∼10 Ma. Assuming instantaneous Earth formation, the upper bound on radiogenic energy supplied by the most powerful short-lived radionuclide 26Al (t1/2 = 0.7 Ma) is 5.5×1031 J, which is comparable (within a factor of a few) to the planet's gravitational binding energy.
KW - Al
KW - K
KW - beta decay
KW - exoplanets
KW - geoneutrinos
KW - radiogenic heat
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U2 - 10.1029/2019GC008865
DO - 10.1029/2019GC008865
M3 - Article
AN - SCOPUS:85088580122
SN - 1525-2027
VL - 21
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
IS - 7
M1 - e2019GC008865
ER -