Never Seen Before: Something Unusual Is Hiding Beneath Bermuda’s Ocean Floor

A particularly interesting discovery beneath the Atlantic Ocean is changing the way scientists think about the geology of Bermuda. A huge rock layer 20 km thick has been discovered, and is located between the oceanic crust and the Earth's mantle. It is unusual for something this size to be located between these two parts of the Earth's composition. According to Live Science reports, the traditional model for the creation of oceanic plates has been altered due to the discovery. In general, the oceanic crust is located on top of the mantle, which is separated from the crust by the Mohorovičić discontinuity.

The rock layer seems to be less dense than the mantle beneath it, but denser than the crust above. This difference in density could probably help explain one of Bermuda’s long-standing geological mysteries. The island sits on a large oceanic swell, which is an area of seafloor that is unusually elevated in comparison to the surrounding ocean basin. Geologists have found it difficult to explain why this swell remains elevated because Bermuda’s volcanic activity stopped around 31 million years ago. Bermuda has remained higher than expected for millions of years, despite oceanic islands generally sinking as their underlying crust cools and becomes denser.

The newly discovered rock layer could provide a possible explanation because of its slightly lighter than the surrounding mantle. It may act like a buoyant platform beneath the island, which would help support the elevated seafloor and prevent it from sinking as quickly as other parts of the ocean floor. Scientists discovered the structure using seismic wave analysis. When earthquakes occur anywhere on Earth, the vibrations travel through the planet’s interior. Researchers can map hidden structures beneath the surface by measuring how these waves change speed as they pass through different rock layers. In this case, seismic data showed patterns that did not match the expected crust-to-mantle transition. Instead, the waves suggested a thick zone of different material which was sandwiched between the two layers.


The process through which this strange structure formed is still not fully understood. Some believe it cooled as the volcanic history of Bermuda was coming to an end, which turned it into solid rock. Another theory is that water reacted with the minerals found in rocks beneath the Earth’s surface. This reaction decreased the rocks' density and changed their shape. Whatever the process was, it is another reminder of how complex the Earth is. The oceanic crust was believed to be stacked up neatly in layers. However, with the discovery of this strange structure, it is possible that other parts of the ocean floor have hidden geological structures beneath their surface. The discovery is also a testament to the fact that modern technology is enabling scientists to explore parts of the Earth they could not previously access. As scientists dig deeper into the deep geological history of Bermuda, the island may be able to reveal new secrets about how volcanic islands are formed, changed, and preserved over time.