We’ve sent spacecraft billions of kilometers into space, yet we’ve barely scratched the surface of our own planet. Literally. The deepest hole ever drilled goes down just over 12 kilometers, which is nothing compared to the roughly 6,371 kilometers to Earth’s center. It’s wild to think we know more about distant galaxies than what’s churning beneath our feet.
This knowledge gap becomes especially frustrating when you consider the boundary between Earth’s mantle and core. That’s where the real action happens, and scientists are now discovering it’s way more complex than anyone imagined.
Continent-Sized Hot Blobs Sitting 2,900 Kilometers Down
Researchers from the University of Liverpool just published something pretty remarkable in Nature Geoscience. They found magnetic evidence of two absolutely massive formations of superheated rock sitting at the base of Earth’s mantle, one beneath Africa and another under the Pacific Ocean. These aren’t small features. They’re continent-sized structures that have been influencing our planet’s magnetic field for millions of years.
The team discovered these giant blobs are surrounded by a pole-to-pole ring of cooler material, creating sharp temperature contrasts that affect how liquid iron moves in the outer core below them. Think of it like dropping ice cubes into hot water, except the scale is planetary and the consequences last for geological ages.
Supercomputers and Ancient Rocks Tell the Story
Figuring this out wasn’t easy. The researchers combined palaeomagnetic data from rocks collected worldwide with advanced computer simulations of the geodynamo. That’s the fancy term for how Earth generates its magnetic field through the movement of liquid iron in the outer core, kind of like a planetary-scale generator.
Even with a supercomputer, running these simulations across 265 million years required massive computational power. But the results were worth it. The models showed that beneath these hot rock structures, the liquid iron might actually stagnate rather than flow vigorously like it does under cooler regions.
Professor Andy Biggin, who studies geomagnetism at Liverpool, explained that some components of Earth’s magnetic field have stayed relatively stable for hundreds of millions of years while other aspects changed dramatically. The science behind understanding these patterns opens up entirely new ways of thinking about our planet’s interior.
Everything We Thought About Earth’s Magnetic Field Might Be Wrong
Here’s where things get really interesting. For decades, scientists studying ancient continental configurations, climate patterns, and even the formation of natural resources assumed Earth’s magnetic field behaved like a perfect bar magnet aligned with the planet’s rotational axis when averaged over long periods.
Turns out that assumption might not be quite right. These findings suggest the deep Earth has strong temperature contrasts that create more complexity than the simple models predicted. This has implications for understanding everything from how Pangaea formed and broke apart to questions about ancient climate and biology.
The DEEP research group, which conducted this study, was established in 2017 specifically to reconstruct Earth’s magnetic field history using rocks from around the world. Their work with colleagues from the University of Leeds is revealing just how dynamic and interconnected our planet’s internal systems really are.
The fact that these enormous superheated structures have been quietly shaping our magnetic field for millions of years, completely hidden from view, makes you wonder what else might be going on down there that we haven’t discovered yet.
