Scientists Discover Billion-Year-Old “Continent-Sized” Blobs Deep Inside Earth
By [James Dinneen]
The Mystery of Earth’s Deep Mantle
Deep beneath our feet, hidden within the swirling currents of molten rock, lie two colossal structures—each as vast as a continent. These enigmatic formations, known as Large Low-Shear-Velocity Provinces (LLSVPs), have puzzled scientists for decades. Now, new research suggests they may be among the oldest and most stable features on Earth, surviving billions of years of planetary turbulence.
Seismic Waves Reveal Earth’s Hidden Secrets
When a massive earthquake strikes, the entire planet vibrates like a giant bell, sending seismic waves rippling through its layers. By analyzing these waves, scientists first detected the LLSVPs—one beneath Africa and another beneath the Pacific Ocean. These structures stretch nearly 1,000 kilometers upward from the boundary between Earth’s molten outer core and its thick, slow-moving mantle.
What makes them unusual? Seismic waves travel more slowly through these regions, hinting at a different composition than the surrounding rock. But until now, their origins and true nature remained a mystery.
A Surprising Discovery: Stability Against the Odds
A team of researchers led by Dr. Arwen Deuss at Utrecht University in the Netherlands took a fresh approach. Instead of just measuring wave speed, they studied how much energy the waves lost as they passed through the LLSVPs.
What they found shocked them.
Despite being hotter than their surroundings, the blobs barely weakened the seismic waves—something that defied expectations. Normally, hotter material absorbs more energy, causing stronger damping. But these structures behaved differently.
Why?
The team proposed that the LLSVPs must be made of dense, crystalline minerals that resist melting and deformation. This would make them highly viscous, allowing them to remain intact even as the mantle slowly churns around them.
A Window Into Earth’s Distant Past
If the LLSVPs are indeed this stable, they could be ancient relics—possibly dating back to Earth’s formation over 4 billion years ago.
Some scientists speculate they might contain primordial material, untouched since the planet’s earliest days. Occasionally, this material could rise to the surface through volcanic eruptions, offering rare glimpses into our planet’s infancy.
“These structures could be time capsules,” says Deuss. “They might hold clues about how Earth evolved—and even how other rocky planets formed.”
What’s Next?
While the findings are groundbreaking, many questions remain:
- How did these structures form?
- Do they influence volcanic activity or plate tectonics?
- Could similar features exist on other planets?
Future research, including advanced seismic imaging and lab experiments, may help unravel these mysteries.
Why Does This Matter?
Understanding Earth’s deep interior isn’t just academic—it could reshape our knowledge of:
✔ Planetary formation
✔ Volcanic hotspots (like Hawaii and Iceland)
✔ The long-term fate of our planet’s geology
As technology improves, scientists may finally decode the secrets of these hidden giants—revealing stories written in stone since before life began.
Sources:
- Utrecht University Seismology Lab
- Nature Geoscience
- Journal of Geophysical Research
Image Credits:
- (Hypothetical mantle illustration)
- (Seismic wave diagram)