Map captures Earth’s antineutrino glow
Planet’s crust, nuclear reactors are hot spots in newly released image
Each second, more than 10 septillion (1025) antineutrinos race away from Earth and into space. That’s 100 trillion times as many antineutrinos as stars in the galaxy. But who’s counting?
Leave that to particle physicist Shawn Usman of the National Geospatial-Intelligence Agency in Springfield, Va. In September in Scientific Reports, he and colleagues published the first global map of antineutrinos, harmless subatomic particles (and the antimatter cousins of neutrinos) born when radioactive elements break down. That decay happens within the planet’s crust and mantle and in nuclear reactors.
Usman’s team pieced together data, including measurements from detectors in Italy and Japan, to build a Technicolor map of antineutrino abundance. Dark reds flag hot spots; blues mark areas where antineutrinos are less bountiful.
The map could help scientists nail down the driver of Earth’s internal heating system, which fuels plate tectonics and volcanoes. Just how much heat comes from radioactive energy in the planet is still up for debate, Usman says. His team’s map might offer researchers a clearer picture. And it will certainly be more colorful.
All over the map
Antineutrinos emerge from land and sea all across the globe, but some spots are especially active (or especially quiet):
1. Fission in progress Nuclear power plants, including the 58 in France, stand out like pimples. Reactors are the only source of human-made antineutrinos, which are created during fission.
2. Mountain peak Earth’s crust beneath the Himalayas and other mountain ranges is especially dense, leading to high concentrations of radioactive elements such as thorium, uranium and potassium.
3. Ocean doldrums The deepest blue region is in the Pacific, which holds very little antineutrino-emitting crust. But it might be a great place for scientists to detect antineutrinos emanating from deep within Earth’s mantle.