NATURE (2023)
Schematic illustration of core to feather transfer.
JAKARTA, KOMPAS — A joint team consisting of a number of geochemists has confirmed high levels of helium-3 in rocks on Baffin Island, Arctic Archipelago, Canada. The discovery of an ancient isotope of helium-3 that was formed in the planet’s formation phase and stored in the Earth’s core provides new evidence of suspected leaks from within.
This new evidence of leakage from the Earth’s core was reported by researchers from the Woods Hole Oceanographic Institution and the California Institute of Technology in the leading journal Nature on Wednesday, October 18 2023.
Previous research found the element helium-3 in lava flows on Baffin Island, which hinted at a possible leak in the Earth’s core. This is because it is an ancient isotope, this isotope was commonly found at a time when the Earth was forming and is trapped in the Earth’s core.
However, because of its nature, helium-3 that reaches the surface is immediately released into the atmosphere and disappears into space. So, helium-3 is rare. If it is found on the surface, it most likely made its way out of the core.
Also read: The Earth’s Core Begins to Rotate in the Opposite Direction
To further investigate the possibility of a leak in the Earth’s core, the research team probed to Baffin Island and began testing several lava flows. They found much higher levels of helium-3 than observed in previous research—higher than anywhere else on Earth.
They also found a high ratio of helium-3 to helium-4 (a common isotope)—the highest ever measured in terrestrial rocks. The high ratio, according to the researchers, is another factor indicating that helium-3 is leaking from the core.
They found much higher levels of helium-3 than observed in previous research—higher than anywhere else on Earth.
The research team notes that finding high levels of helium-3 on Earth is a big deal. Because, if it can be proven that the material is indeed leaking from the core, this will give scientists a way to study core material that has never been done before. This could reveal more about the atomic nucleus than previously thought. They note that if helium-3 originates from the core, then other surrounding material must also do so, providing a further physical example of core material.
Leak theory
Previously, two geoscientists, one from Princeton University and another from the Guangzhou Institute of Geochemistry, had developed a theory to explain how helium-3 leaks from the Earth’s core into the mantle. In their study, reported in the journal Nature Geoscience in May 2023, Jie Deng and Zhixue Du used first-principles calculations to show that helium-3 can insert magnesium oxide at the core-mantle boundary, allowing it to enter the mantle.
NATURE GEOSCIENCES (2023)
Two-phase simulation of He partition at core-mantle boundary conditions. (a) Snapshot at 47520 fs from a two-phase coexistence simulation of solid Mg64O64He4 and liquid Fe96He4 at 4000 K and ~135 GPa. (b) The corresponding instantaneous coarse grain density profile (blue dots) along the z-axis of the simulation box and the best fitting curve using Eq. 2. The two dashed lines (z0 and z1 in Equation 2) are the locations of the Gibbs separation surfaces. The red shaded area is the interface.
Helium-3, a helium isotope with one neutron in its nucleus instead of the usual two, is extremely rare on Earth’s surface. However, recent research shows that it can be found in volcanic rock formations on the sea floor. These findings suggest that some process allows helium-3 to seep from the core into the mantle. Scientists want to obtain more helium-3 because it has proven useful in fusion reactors as a fuel source.
Previously, scientists believed there was a large amount of helium-3 locked in Earth’s core—planetary scientists believed helium-3 was there during the planet’s formation. Helium-3 is a constituent of dust and gas that fused about 4.5 billion years ago. And, because of its nature, it becomes locked within the core. However, there is a process that allows some of it to escape into the Earth’s mantle, and now, Deng and Du believe they may have figured out why.
Also read: Earthquakes, Signaling Changes in the Rotation of the Earth’s Core
Previous research has shown that when helium-3 comes into contact with magnesium oxide, it exfoliates, meaning it changes from a homogeneous starting mineral to one that has a crystalline phase. As part of the process, helium is physically transferred to the magnesium oxide site.
The researchers mathematically showed that helium-3 could have been withdrawn from the core through interactions with magnesium oxide shortly after the planet formed, and continues to do so today. Their calculations suggest that over the planet’s lifetime, as helium-3 was lost, it could have slowly reached the mantle, and possibly risen to the surface through volcanic activity.
2023-10-21 11:59:53
#Evidence #Earths #Core #Leakage #Baffin #Island #Canada
