Scientists have concluded that more than half of the Earth’s heat is due to nuclear fission process and it results in the movement of earth’s continent and crust.
The confirmation comes after scientists used a Borexino and Neutrino detector in Japan and Italy- the Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND) to measure the flow of antithesis of these neutral particles (anti-neutrinos) that emanate from the Earth. (Detailed Results — July 17 in Nature Geoscience.)
Our Earth has many radioactive elements present in it such as uranium, thorium, potassium, etc. Once the radioactive materials are decayed, they release energy(heat) and anti-neutrinos. Since neutrinos and anti-neutrinos (geo-neutrinos) don’t have charges, they can travel through mass and space freely. The scientist can determine the amount of heat that results from radioactive decay by measuring these particles.
The scientists found that around 20 Terawatts of earth’s heat is resulted from the antineutrino emission which is almost as twice as the energy used by humans at present. If this massive energy is combined with 4 Terawatts of decaying potassium then it can move mountains or cause the collisions which created them.
The accurate measurement was made possible by the shutdown of the Kashiwazaki-Kariwa nuclear reactor following an earthquake in Japan (2007). If the plant hasn’t been shutdown then the particles would mix with naturally emitted geo-neutrinos. It would have made difficult for the KamLAND team to make correct measurement.
The detector used can hide from cosmic rays – properties similar to neutrinos and anti-neutrinos. The detector, 13 meter in diameter, is a transparent balloon filled with a mixture of special liquid hydrocarbons. The hydrocarbons itself suspends in a bath of mineral oil which was contained in an 18 meter diameter stainless steel sphere and it is covered on the inside with detector tubes. The detector captured the telltale mark of some 90 geo-neutrinos over the course of seven years of measurements.
The measurements suggest that more than half of the Earth’s heat is due to radioactive decay and it is estimated around 44 terawatts on the basis of temperature found at the bottom of deep boreholes into the planet’s crust. The decay happens in the crust and mantle of the Earth and some of the heat might have been trapped in Earth’s molten iron core. The Earth is unlikely to cool because of the heat pumped out of fission process, and because of long half-lives of these elements it will prevent the collision of continents.
[via Scientific American]