Scientists have uncovered an intriguing mystery beneath Bermuda. A thick layer of rock, about 12.4 miles deep, lies below the ocean crust in this iconic archipelago. This layer’s size is unprecedented compared to similar formations elsewhere.
William Frazer, a seismologist from Carnegie Science, explains that typically, you’d expect to hit the mantle right after the oceanic crust. However, Bermuda has this unique layer beneath it, raising questions about how it formed.
While the origins of this rock layer remain unclear, it might help explain Bermuda’s geological oddity. Despite no volcanic activity for 31 million years, Bermuda sits on an ocean swell where the crust is elevated without any signs of eruptions.
“This structure suggests that the last volcanic activity might have pushed mantle rock into the crust, creating a sort of ‘raft’ that keeps the ocean floor elevated by around 1,640 feet,” Frazer notes.
Bermuda often gets associated with the Bermuda Triangle, a region infamous for mysterious disappearances of ships and planes. However, the real enigma lies in its oceanic swell, which remains puzzling since comparable swell formations typically fade when volcanic activity ceases.
Frazer and Jeffrey Park, a professor at Yale, studied seismic waves from global earthquakes to discover the unusual rock layer under Bermuda. Their research, published in Geophysical Research Letters, shows this hidden layer is less dense than the surrounding rock.
Sarah Mazza, a geologist at Smith College, shares that remnants of past volcanism are likely still impacting Bermuda’s geology today. Her own research suggests that minerals found in Bermuda’s lava indicate a unique volcanic history connected to deep mantle processes, dating back to the formation of the supercontinent Pangea.
Mazza explains that while Hawaii’s islands form via mantle hotspots, Bermuda’s geology is influenced by its historical location at the core of the last supercontinent. “Understanding this region helps us learn more about Earth’s processes,” she states.
Frazer is now looking at other islands for similar formations. “Studying Bermuda helps us grasp both extreme and typical geological processes on Earth,” he adds. This ongoing inquiry not only promises to shed light on Bermuda’s mysteries but also on the broader dynamics of our planet’s geology.
For more details on geological research, check out the findings published in Geophysical Research Letters.
