How Geoneutrinos Help Scientists Map Earths Hidden Interior Heat

Scientists tracking subatomic particles generated by radioactive decay inside Earth have encountered uncertainties, as wired.com reported. The flux of geoneutrinos indicates that elements heating the mantle could account for anywhere from a small percentage to half of the planet’s internal heat.

Radioactive Heat Discrepancy Complicates Mantle Mapping

The uncertainty in geoneutrino estimates represents a thermal discrepancy equivalent to the output of tens of thousands of nuclear power plants. This lack of precision makes it difficult for researchers to detect distinct chemical differences between specific sections of Earth’s mantle.

Neutrinos pass through solid rock completely unhindered, providing a direct line of sight into inaccessible regions thousands of kilometers below the surface. Geoneutrinos are specifically electron antineutrinos produced when radioactive isotopes such as uranium, thorium, and potassium decay deep within the crust and mantle, powering mantle convection, plate tectonics, and the magnetic field.

SNO+ Detection Precedes Large-Scale Experiments in China

The detection at the SNO+ experiment arrives as the field of geoneutrino research experiences a surge of activity. Another major neutrino facility, known as JUNO, is currently collecting data in China and is expected to report its first geoneutrino flux later this year, adding a fourth and significantly richer view to global research efforts. Located under a mountain outside Guangzhou, JUNO features more than 20,000 tons of liquid scintillator in a giant acrylic or stainless-steel sphere surrounded by thousands of light sensors.

JUNO’s massive scale means it is expected to detect more geoneutrinos in its first year of operation than the combined output of Kamland, Borexino, and SNO+ over several decades.

Ocean-Bottom Detectors Target Mantle-Only Territory

While clearer estimates of geoneutrino flux may arrive from more detailed geological data and continued counts at existing experimental sites, researcher McDonough advocates for a more radical installation.

Because oceanic crust is thinner and more uniform, crust-related uncertainties would drop substantially, placing instruments directly in mantle-only territory. Although an ocean-bottom detector carries an estimated cost of hundreds of millions of dollars and has received little traction from government funders so far, McDonough expressed hope that momentum could build in China, which has already approved other large geoscience projects.

It’s very possible.

McDonough