Scientists from Caltech and the Woods Hole Oceanographic Institution (WHOI) have discovered evidence that the Earth's core is leaking. High concentrations of a specific helium isotope have been found in Canadian lava flows, which the team believes originated from the Earth's core.
While we seem content to waste helium by blowing it into balloons, helium is relatively scarce on Earth. Why? Your first instinct is probably right - helium literally floats into the upper atmosphere, often escaping into space. However, there are some reserves of helium deep underground in the Earth's mantle and core, remnants of when the Earth formed from a nebula that gave birth to the Sun.
In the new study, researchers from Caltech and the World Health Organization's Institute of Science investigated lava flows on Canada's Baffin Island, where previous teams had found traces of helium-3, an isotope of helium that is particularly rare on Earth. Sure enough, the scientists found that the ratio of helium-3 to the more common helium-4 is higher than anywhere else on Earth, 67 times higher than in the atmosphere.
Earth's mantle appears to be the culprit, but scientists say that doesn't match the specific isotope ratios they detected for helium, strontium, neodymium and lead. Instead, their evidence points to the Earth's core as the most likely source.
Of course, more work remains to be done to confirm whether the Earth's core is leaking this helium to the surface. But if that's true, the team says, then other material in the region should also come from the core, which could give scientists a valuable look at a part of the planet that's difficult to study for obvious reasons.
The research was published in the journal Nature.