Scientists have discovered a massive blob of hot rock nearly 250 miles underground beneath the Appalachian Mountains, stretching across six states including Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. The Northern Appalachian Anomaly (NAA) is moving south towards New York City at a rate of about 12 miles every million years, predicting it will reach the city in approximately 15 million years.
Researchers from the University of Southampton in the UK and the Helmholtz Center for Geosciences in Germany used seismic tomography to detect the anomaly. Unlike typical hot spots near volcanoes, this blob is far inland and hidden beneath ancient mountains. It’s believed to be part of a slow-moving “mantle wave,” a chain reaction of sinking and rising rock set in motion 90 million years ago when North America split from Europe.
The study’s findings challenge the idea that the eastern US is geologically dead, suggesting similar drips may have shaped America’s mountains millions of years ago. The blob is thought to be created by a Rayleigh-Taylor instability, where denser material sinks into the mantle, pulling lighter rock upward. This process may contribute to fewer earthquakes in the Northeast due to the softer, more flexible mantle.
The NAA is currently near the boundary of a deep geological structure formed by the Laramide Orogeny, an ancient tectonic breakup that occurred around 1.5 million years ago. The study’s authors propose that these “drips” migrate inland over time, away from the rift, and may still be active today, potentially creating new blobs in the future.
Source: https://www.dailymail.co.uk/sciencetech/article-14960643/200-mile-long-mystery-blob-new-york-earth.html