By STACY LIBERATORE, US SCIENCE & TECHNOLOGY EDITOR
Published: 20:29 BST, 14 August 2026 | Updated: 21:06 BST, 14 August 2026
Scientists probing an ancient hot ‘blob’ moving toward New York City discovered a mysterious column lurking nearby.
Called the Northern Appalachian Anomaly (NAA), the roughly 250-mile-wide mass is composed of unusually hot rock buried deep beneath New England.
A 2025 study found that the NAA is drifting southwest at approximately 12 miles per million years and could pass beneath New York City within 10 to 15 million years.
Researchers have now used seismic waves from distant earthquakes to create the most detailed three-dimensional images yet of the anomaly and surrounding mantle.
The scans revealed that the blob extends from approximately 37 to 124 miles beneath New England and is confined to the upper mantle.
But they also exposed a separate, narrow column beneath Connecticut that plunges hundreds of miles deeper.
Unlike the hot blob, which slows seismic waves, the column allows them to travel unusually quickly, suggesting it is made from colder, denser material.
Scientists believe it could be a fragment torn from the rocky underside of North America or the sinking side of a vast current circulating through the mantle.
Scientists believe a nearly 250-mile blob called the Northern Appalachian Anomaly is still moving and shaping mountains in the US
The latest study was led by researchers from Yale University and the University of Minnesota and published in the Journal of Geophysical Research: Solid Earth.
The team created the underground images using seismic tomography, which works in a similar way to a medical CT scan.
Instead of X-rays passing through a human body, the technique measures the time taken for seismic waves from distant earthquakes to travel through different parts of the planet.
Those waves slow down or accelerate depending on the temperature, density and composition of the rock they encounter.
