[Rockhounds] Earth's Core Seems to Be Leaking, And Scientists Think They Know Why

[Kreigh Tomaszewski]

Record concentrations of a helium isotope found inside 62-million-year-old
Arctic rocks could be the most compelling evidence to date of a slow leak
in our planet's core.

Building on the results of a previous analysis
<https://linkinghub.elsevier.com/retrieve/pii/S0012821X21000212> of ancient
lava flows, a team of geochemists from Woods Hole Oceanographic Institution
and the California Institute of Technology are now more certain than ever
that helium trapped in the core as our planet was forming is making its way
to the surface.

Helium isn't the kind of element that makes friends easily. Being so light
and non-reactive, there's little to stop the gas from diffusing out of
exposed rocks into the atmosphere and drifting off into space.

That makes helium a surprisingly rare material on the planet's surface. Yet
just how much of the element remains trapped deep beneath our feet is one
of the great unknowns in geology.

After around 4.6 billion years of spitting lava, most of the helium Earth
swallowed as an infant should have been burped away. So any traces of the
gas found in relatively fresh deliveries of volcanic rock ought to have
come from pockets of mantle that are yet to cough up their helium, or from
a slow-leaking reserve.

Basaltic lavas on Canada's Baffin Island contain some of the world's
highest ratios of helium 3 <https://en.wikipedia.org/wiki/Helium-3> (3He)
to the slightly heavier isotope, helium 4
<https://en.wikipedia.org/wiki/Helium-4> (4He). To geologists, such a mix
indicates the gas's presence isn't contamination by the atmosphere, but
rather a sign of deeper, more ancient origins.

https://www.sciencealert.com/our-planets-core-seems-to-be-leaking-and-scientists-think-they-know-why