Scientists discover massive rock layer under Bermuda
Scientists from Carnegie Science and Yale have uncovered a giant, 20km-thick rock layer beneath Bermuda by studying earthquake waves.
This low-density layer sits below the ocean floor and is much thicker than similar layers found at other islands.
The findings were published in November 2025.
What makes this layer special?
Unlike usual formations, this rock sits inside the tectonic plate—not just under the crust—and is about 1.5% less dense than the surrounding mantle.
It likely formed 30-35 million years ago when magma rich in carbon was injected into the crust during Bermuda's last eruption and then cooled off.
Why does it matter for Bermuda?
This buoyant layer actually helps keep Bermuda elevated—raising the seafloor by about 500 meters—even though volcanic activity there stopped ages ago.
As geologist Sarah Mazza put it, leftover material from this ancient process still shapes how high Bermuda stands today.
Could this change what we know about islands?
The discovery could shake up what scientists think about how ocean islands form and stay afloat.
Researchers now want to check if other islands have hidden layers like this—which might mean rethinking some big ideas in geology.