Scientists confirm Earth's core is seeping

Join CNNs Wonder Theory science newsletter to get updates on exciting discoveries, scientific progress, and beyond. Recently, researchers on Canadas Baffin Island made a remarkable finding in volcanic rocks. They uncovered a significant quantity of a scarce type of helium known as helium-3. This discovery provides further evidence to support the hypothesis that this noble gas has been escaping from Earth's core for thousands of years.

The research team found helium-4 in the rocks, which is more common on Earth. However, they were surprised to discover a higher quantity of helium-3, which is typically found more easily in other parts of the universe. The discovery was recently published in the journal Nature.

Lead study author Forrest Horton, an associate scientist in the department of geology and geophysics at Woods Hole Oceanographic Institution, explained that there is a significant disparity between the levels of helium-3 and helium-4 in the universe.

This photograph shows ripples in the surface of Denman Glacier in East Antarctica that throw shadows against the ice. The glacier is melting at a faster rate now than it was from 2003 to 2008.

NASA

Scientists have uncovered an ancient terrain in a region on Earth that is relatively unfamiliar compared to the surface of Mars. According to Horton, "3He is not commonly found on Earth due to its limited production and minimal addition to the planet. Moreover, it tends to escape into space as Earth's rocky layer moves and circulates, resembling the movement of boiling water on a stove. As this material rises, cools down, and subsequently descends, helium is released into the atmosphere and eventually lost to space."

await discovery by detecting elements that escape from Earth's core. These valuable insights reveal the mysteries surrounding our planet's origin and evolution, further reinforcing an established hypothesis that explains its formation.

Baffin Island, situated in Nunavut, is Canada's largest island and the world's fifth-largest. During her doctoral research supervised by Finlay Stuart from the University of Edinburgh, Solveigh Lass-Evans identified a significant helium-3 to helium-4 ratio in volcanic rocks on Baffin Island. The findings were published in Nature in 2003.

The composition of a planet reflects the elements involved in its formation. Previous research suggested that the presence of small amounts of helium-3, leaking from Earth's core, supports the commonly accepted theory that our planet originated from a solar nebula. This nebula is a cloud of gas and dust that likely collapsed due to the shock wave of a nearby supernova, which contained this element.

Building upon this research, Horton and his colleagues conducted a study on Baffin Island in 2018. They focused on the lava that erupted millions of years ago when Greenland and North America separated, creating a new seafloor. The team aimed to investigate the rocks in order to gain insights into the composition of Earth's core and mantle, which form the solid layer beneath the Earth's surface.

Baffin Island is home to mountains and steep cliffs.

The researchers journeyed to the isolated island aboard a helicopter, venturing into a surreal and distant scenery adorned with colossal cliffs carved by lava flows. Enormous icebergs gracefully drifted nearby, while polar bears stealthily patrolled the coastline. In their pursuit, the researchers received invaluable support from local organizations such as the Qikiqtani Inuit Association and Nunavut Research Institute, who facilitated access, offered guidance, and ensured their safety in the presence of the bears, according to Horton.

"This region in Baffin Island holds significant significance, serving as sacred grounds for the local communities while also providing a scientific perspective into the depths of the Earth," he commented.

The examination of Arctic rocks by Horton and his team unearthed unexpectedly elevated levels of helium-3 and helium-4 in contrast to previous research findings. Furthermore, the measurements displayed variation across the collected samples.

"Breaking off fresh pieces of the lavas with a rock hammer was just as exciting as cracking open geodes during childhood, as each rock held the potential of discovering a precious treasure - bright green olivine, also known as the gemstone peridot," Horton expressed. "And what a remarkable scientific discovery they turned out to be!"

Horton explained that for every million helium-4 atoms, there exists approximately only one helium-3 atom. The team conducted measurements which revealed that each gram of olivine crystals contained around 10 million helium-3 atoms.

"Our significant measurements of the high 3He/4He ratios suggest that gases, which are likely inherited from the solar nebula during the formation of the solar system, are more effectively conserved in Earth than previously anticipated," he stated.

Tracing the history of Earth

However, the origin of the helium-3 present in the rocks can be traced back to the early stages of the universe, specifically the big bang. During this event, the universe was formed and a large amount of hydrogen and helium was released. These elements gradually became part of galaxy formation processes.

The image depicts the average temperature (in degrees Celsius) during the warmest month for both Earth and the projected supercontinent, Pangea Ultima, in 250 million years. This timeline represents a harsh environment where the survival of most mammal species would be extremely challenging.

University of Bristol

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Our solar system is thought to have originated 4.5 billion years ago from a solar nebula, with the collapse of a dust cloud in a supernova leading to the formation of a spinning disk from which our sun and planets emerged, as stated by NASA.

During the planet's formation, helium from the solar nebula is believed to have become trapped in Earth's core, resulting in the core becoming a storage place for noble gases. As helium-3 escaped from the core, it rose to the surface through the mantle in the form of magma plumes, eventually erupting on Baffin Island.

According to Horton, most of the gases in the magma were released into the atmosphere during the eruption. However, the helium from the deep Earth was preserved in the olivine crystals that formed before the eruption.

The recent study lends support to the notion that helium-3 has been seeping out of Earth's core for an unspecified duration. Nonetheless, the researchers are uncertain about the exact commencement of this phenomenon.

"The lavas, estimated to be approximately 60 million years old, suggest that the mantle plume ascended over a period of possibly tens of millions of years," Horton explained. "Therefore, the helium detected in these rocks might have escaped the Earth's core approximately 100 million years ago, or possibly even earlier."

According to Horton, the leakage of helium from the Earth's core does not pose any threat to our planet or have any adverse consequences. Being a noble gas, helium does not undergo chemical reactions with matter, thus it does not affect humanity or the environment in any way.

Next, the research team is interested in exploring whether the core serves as a repository for various light elements, potentially explaining the lower density of Earth's outer core compared to predictions.

"Could the core play a significant role in housing elements such as carbon and hydrogen, which are crucial for the habitability of planets? And if this is the case, could the release of these elements from the core throughout Earth's history have influenced planetary evolution? I am eager to investigate the connections between helium and other light elements,” shared Horton. “Perhaps helium can serve as a tracer for identifying other elements as they cross the boundary between the core and mantle."