Geoneutrinos offer an indirect way to investigate Earth’s hidden radioactive inventory: underground detectors register antineutrinos produced by uranium and thorium decay, and scientists compare those observations with geological models. The result is a model-constrained view of radioactive heat—not a direct image of Earth’s interior or a map of water and every volatile substance.
What are geoneutrinos?
Geoneutrinos are electron antineutrinos produced by radioactive decay inside Earth. In the detector analyses discussed here, the main sources are the decay chains of uranium-238 and thorium-232. These particles can travel through the planet and reach detectors far below ground, where a small number of interactions can be identified against background signals.
As an Amazon Associate I earn from qualifying purchases.
The detector records candidate interactions, not underground rock types. Turning those events into statements about Earth requires a second step: estimating how much uranium and thorium are present in the crust and mantle, and where those elements are distributed.
How do geoneutrinos map Earth’s interior?
Measurements constrain a model; they do not make a photograph
AGM2015 is a global model of energy-dependent antineutrino flux at Earth’s surface. Published in 2015, it combines vertically structured crust models with a mantle model and uses observations from KamLAND in Japan and Borexino in Italy as constraints. It predicts where flux is expected under its assumptions; it does not provide a fully resolved three-dimensional photograph of geology.
#1 Best Overall
The model’s predictions remain uncertain because scientists do not know the exact abundance and distribution of radioactive isotopes inside Earth. A useful companion, Geoneutrinos.org, lets users explore predicted flux and signals for chosen uranium and thorium concentrations, including with a two-layer mantle solver. It is a way to explore model assumptions, not an independent measurement.
Why the crust matters to a mantle claim
Geoneutrinos detected at a site can originate in both the crust and mantle. The crust is relatively thin, but its contribution cannot be ignored: a 2013 reference Earth model estimates that continental crust makes up about 0.5% of bulk silicate Earth mass while supplying almost one third of its radiogenic heat power. Because crustal uranium and thorium near a detector affect the expected signal, estimating a mantle contribution depends on detailed local geology and on subtracting the crust contribution.
What did Borexino measure?
In a 2020 analysis using 3,262.74 days of data collected from December 2007 through April 2019, the Borexino Collaboration reported a total geoneutrino signal of 47.0 TNU. Its statistical uncertainty was +8.4/−7.7 TNU and its systematic uncertainty was +2.4/−1.9 TNU. These are the results of that detector analysis, not a model-free count of Earth’s radioactive inventory.
Recommended Free Tools
When the analysis used detailed knowledge of the local crust, it excluded the mantle-signal null hypothesis at 99.0% confidence. That confidence statement concerns whether the data support a nonzero mantle contribution under the analysis; it does not establish one exact mantle composition.
Rank #3
Under the paper’s interpretation, the estimated radiogenic heat from uranium and thorium in the mantle was 24.6 +11.1/−10.4 TW. This is a mantle U/Th estimate, not the total heat escaping from Earth. Its interpretation depends on the signal analysis and geological modeling.
Can geoneutrinos reveal Earth’s missing potassium?
Not through the cited uranium-and-thorium maps. Uranium and thorium are classified as refractory lithophile elements, while potassium is a volatile lithophile element. The distinction matters because potassium is relevant to questions about Earth’s hidden volatile inventory as well as its internal heat budget.
A 2026 article, “Probing Earth’s missing potassium using the antimatter signature of geoneutrinos,” describes a possible future approach to detecting potassium-40 geoneutrinos. That is a prospective measurement, not an established potassium signal. Existing U/Th geoneutrino observations do not directly measure water, and they cannot be presented as a map of all volatile substances.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWhat comes next?
JUNO in China completed filling its 20,000-ton liquid-scintillator detector and began data-taking on 26 August 2025. The Chinese Academy of Sciences lists geoneutrinos among the facility’s science targets, alongside reactor, solar, supernova and atmospheric neutrinos. The announcement establishes that data-taking began and that geoneutrinos are a planned target; it does not report a JUNO geoneutrino discovery.
Best Value
For future measurements, more detector exposure can improve the event sample, while better regional crust models can sharpen the separation between crustal and mantle contributions. Any resulting interior map will still be an inference combining particle observations with Earth models.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
