Bermuda often brings to mind stories of mystery and adventure, but a new geological find is adding depth to our understanding of this island. A recent study in Geophysical Research Letters reveals a surprising 12.4-mile-thick structure lying beneath the ocean floor. This discovery could shake up our views on how Bermuda was formed and why it sits where it does in the Atlantic Ocean.
Researchers from Carnegie Science and Yale University used cutting-edge seismic imaging to uncover this thick layer of rock, which isn’t found anywhere else on Earth. According to William Frazer, a seismologist at Carnegie Science, “Normally, beneath the oceanic crust, you’d expect the mantle. But in Bermuda, there’s this other layer right beneath the crust.” This finding leads to new questions about the geological history of Bermuda and how this thick rock layer came to be.
Bermuda is known as an oceanic swell, a place where the ocean floor is higher than its surroundings. Scientists have been puzzled by this for years, especially since its last volcanic activity was over 31 million years ago. Why does this swell exist without any active volcanoes? The newly discovered rock could be the answer. Researchers think that the remnants of old volcanic activity may keep the ocean bed elevated.
Sarah Mazza, a geologist at Smith College, notes, “This leftover material from past volcanism might be holding up the swell.” This suggests that the geological history of Bermuda is quite different from other volcanic islands. Unlike those in the Pacific or Indian Oceans, Bermuda’s volcanic past ties back to the supercontinent Pangea, which began breaking apart around 300 million years ago. This adds layers to our understanding of the island’s geological journey.
What makes this thick rock layer so fascinating is its unique composition. It seems to have survived the test of time, remaining less dense than surrounding materials—possibly pushed up from the mantle during ancient volcanic events. Mazza highlights, “Being located at the heart of the last supercontinent is key to why this structure is unique.” Understanding Bermuda can give us insights into Earth’s geology as a whole.
The carbon-rich lavas found in Bermuda suggest that its volcanic origins differ from those of islands in other ocean regions. This deep material may explain why Bermuda’s volcanic history appears so distinct. According to Frazer, “Learning about extreme places like Bermuda helps us understand less extreme locations.” As scientists delve deeper into Bermuda’s geological secrets, they may unlock valuable information about the Earth’s past and its evolving landscape.
