What lies beneath Bermuda Triangle? Scientists discover rare underwater structure. Here’s what we know

A team of American scientists believes it may have finally solved one of the enduring geological mysteries linked to the Bermuda Triangle, uncovering a hidden structure beneath Bermuda that helps explain why the island remains unusually elevated above the Atlantic seafloor despite its volcanoes becoming inactive more than 30 million years ago. According to the Carnegie Institution for Science, the new research was led by seismologist William Frazer and Jeffrey Park. Their findings suggest Bermuda is supported by a geological structure unlike any previously identified on Earth.

Most volcanic island chains, including Hawaii, are formed above mantle plumes, columns of hot rock rising from deep within Earth’s mantle. These plumes create volcanoes and push the seafloor upwards. Once tectonic plates shift away and volcanic activity ceases, the raised seafloor usually sinks back down over time. However, Bermuda has remained elevated, sitting roughly 1,600 feet above the surrounding ocean floor, according to Carnegie Science.

To investigate the anomaly, Frazer and Park analysed seismic waves generated by major earthquakes around the world. By studying how the waves travelled through Earth and changed speed depending on the material they passed through, the scientists created an image of the planet’s interior beneath Bermuda down to a depth of around 20 miles.

The researchers discovered a layer of rock more than 12 miles thick beneath the oceanic crust. Unlike the denser mantle surrounding it, this rock is comparatively light and buoyant. Rather than a plume actively pushing upwards, the structure appears to act like a raft, helping keep Bermuda and the surrounding seafloor afloat.

The team believes the formation, known as an underplating, dates back to Bermuda’s volcanic past tens of millions of years ago. They say carbon-rich molten mantle rock may have intruded into the base of the crust and cooled there, creating the lighter layer. The material itself could have originated hundreds of millions of years earlier during the formation of the supercontinent Pangaea.

“Bermuda is an exciting place to study because a variety of its geologic features do not fit the model of a mantle plume, the classic way for deep material to be brought to the surface,” Frazer said, according to Carnegie Science.

“We observe thick underplating, something that is not observed at most mantle plumes. Combined with recent geochemical observations, this suggests that there are other convective processes within Earth’s mantle that have yet to be well understood,” he added. Frazer is now searching for similar structures beneath other islands to determine whether Bermuda is unique or part of a broader and previously overlooked geological phenomenon.

The findings have been published in the journal Geophysical Research Letters.