Study of Earth’s Heat Flux by Means of Geoneutrino Detection

The heat flux from the Earth’s interior and its connection with the number of neutrinos recorded by detectors at the Earth’s surface are discussed. The values predicted for the geoneutrino fluxes may be matched with experimental data, but the observed flux of the Earth’s internal heat requires the presence of a larger amount of radioactive elements. The amount of uranium and thorium within the Earth is constrained by measurements performed with the aid of modern geoneutrino detectors. This makes it possible to explain completely a flux of 50 TW. There are indications that the flux from the Earth’s interior is 200 to 250 TW. Such a flux could be explained only by the presence of a substantially larger amount of potassium in the Earth. In order to determine precisely the heat flux from the Earth’s interior, it is necessary to measure completely the flux of antineutrinos from all heat-releasing isotopes, including the flux of neutrinos from 40K decay. Possibly, this flux has already been observed at the Borexino detector.