On the latest episode of things that weren’t on our 2025 bingo cards: somewhere 125 miles under our feet, a molten blob the size of Maine is slowly strolling towards New York City, and geologists are both intrigued and slightly baffled.
Nicknamed the Northern Appalachian Anomaly (NAA), this underground mass of abnormally hot rock is about 220 miles wide and seems to be gliding its way southwest beneath the Eastern U.S., moving at a pace of 12 miles per million years. Yes, per million years.
At that speed, you’ve got time to panic (though you shouldn’t). Or retire.
What Is This Mysterious Blob?
Well, what this mysterious blob definitely isn’t is leftover magma from when North America broke away from Africa–that was 180 million years ago, says geoscientist Tom Gernon.
“This is newer,” he explains, and by “newer” he means a mere 80 million years ago, likely tied to the moment Greenland and North America parted ways, according to new research led by the University of Southampton.
Officially, the NAA is what geologists call a “low-seismic-velocity zone,” which, in layman’s terms, is essentially a hot, gooey rock where sound waves travel slowly.
But being the Eastern U.S. has been tectonically asleep for about 180 million years (read: North America breaking away from Africa), the blob shouldn’t exist–at least not situated under the Appalachian Mountains like it is.
The “Lava Lamp” That Lifts Mountains On Its Journey To New York
To track the blob’s movement, scientists used something called seismic tomography (basically a giant Earth MRI). What they found? The blob behaves like a lava lamp, silently oozing and lifting the Appalachian Mountains from below–like a car jack except, well, for the Earth.
Professor Tom Gernon, lead author of the study from the University of Southampton, says this is part of a much bigger process they call mantle wave theory. He stated:
Heat at the base of a continent can weaken and remove part of its dense root, making the continent lighter and more buoyant, like a hot air balloon rising after dropping its ballast. This would have caused the ancient mountains to be further uplifted over the past few million years.
This movement explains why those mountains are still standing tall, despite millions of years of erosion (wind and rain) and hikers stomping all over them. “It’s like a hidden conveyor belt beneath the continent,” said Gernon. “Even in places that look geologically boring, the deep Earth is still partying.”
What’s Next For This Mysterious Blob?
The good news is, though you have ample time to panic, there’s no need to–this blob isn’t about to pop up in Central Park any time soon.
But according to seismic data and geodynamic simulations, it’s slowly drifting toward the New York region, and may pass directly underneath in about 15 million years.
At that point, if it’s still in its current warm and gooey state, it might help prop up terrain or cause subtle geologic shifts, such as causing the Appalachians to slump oh so slightly. Or, it could just keep sauntering on its merry way, completely unnoticed.
But for now, at the pace the underground heat blob is moving–a pace which, not to mention, is so slow it would furrow the brow of any native New Yorker–you’ll certainly have time to finish your coffee and baconeggncheese. Maybe a few million of them.
