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Reference Models for Lithospheric Geoneutrino Signal

Debate continues on the amount and distribution of radioactive heat producing elements (i.e., U, Th, and K) in the Earth, with estimates for mantle heat production varying by an order of magnitude. Constraints on the bulk-silicate Earth's (BSE) radiogenic power also places constraints on overall BSE composition. Geoneutrino detection is a direct measure of the Earth's decay rate of Th and U. The geoneutrino signal has contributions from the local ($\sim$40$\%$) and global ($\sim$35$\%$) continental lithosphere and the underlying inaccessible mantle ($\sim$25$\%$). Geophysical models are combined with geochemical datasets to predict the geoneutrino signal at current and future geoneutrino detectors. We propagated uncertainties, both chemical and physical, through Monte Carlo methods. Estimated total signal uncertainties are on the order of $\sim$20$\%$, proportionally with geophysical and geochemical inputs contributing $\sim$30$\%$ and $\sim$70$\%$, respectively. We find that estimated signals, calculated using CRUST2.0, CRUST1.0, and LITHO1.0, are within physical uncertainty of each other, suggesting that the choice of underlying geophysical model will not change results significantly, but will shift the central value by up to $\sim$15$\%$, depending on the crustal model and detector location. Similarly, we see no significant difference between calculated layer abundances and bulk-crustal heat production when using these geophysical models. The bulk crustal heat production is calculated as $7 \pm2$~terrawatts, which includes an increase of 1~TW in uncertainty relative to previous studies. Future improvements, including uncertainty attribution and near-field modeling, are discussed.