For decades, Bermuda has carried with it a certain sort of reputation. Mysterious disappearances. Weird compass stories. That kind of thing.
Put it this way — there are enough low-rent documentaries about the place and its strange history to keep cheap TV channels ticking over with content for at least another century or so.
Scientists studying the Atlantic island have now solved a much less dramatic mystery that has baffled geologists for years: why Bermuda is still sticking up out of the ocean at all.
Sorry it’s not the answer to the whole Bermuda Triangle mystery thing (or an explanation as to why people wear Bermuda shorts), but it’s still interesting. We promise.
The small island chain sits around 650 miles east of North Carolina in the North Atlantic.
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Roughly 64,000 people live there today, perched on land that technically shouldn’t still be sitting quite so high above the surrounding sea floor as it does.
Normally, volcanic islands rely on heat from active geology deep below the surface to stay elevated. Bermuda’s volcanoes, however, stopped erupting more than 30 million years ago.
In geological terms, the island should’ve gradually sunk lower over time. Basically, logic would dictate that it should all be submerged, sitting at the bottom of the ocean, Atlantis-style. But it’s not.
Instead, Bermuda has remained unusually raised above the deep Atlantic basin for millions and millions of years.
Scientists have now – finally – found out why. They’ve linked that strange survival to a huge hidden layer of lighter rock that’s buried beneath the island’s ocean crust.
Researchers William Frazer and Jeffrey Park used more than two decades’ worth of earthquake recordings gathered from a single seismic monitoring station on Bermuda. Which is, you have to admit, an impressively comprehensive and patient way to solve any kind of mystery.
By analysing the vibrations produced by distant earthquakes, the team was able to map rock layers stretching more than 25 miles beneath the island.
Pressure waves travelling through Earth change behaviour when they hit different materials, apparently.
That then allowed the scientists to work out what lies underground without having to drill massive holes everywhere. Which might well have upset a few of the locals and visiting tourists.
Their study, published in Geophysical Research Letters, revealed an enormous slab of lighter volcanic rock sitting beneath Bermuda.
The hidden layer measures around 12 miles thick, roughly the same length as Manhattan Island from tip to tip. Or half a marathon, depending on how familiar you are with New York City geography.
This rock beneath Bermuda is believed to be around 1.5% less dense than the surrounding mantle material, making it more buoyant and effectively helping the island float higher above the ocean floor.
That doesn’t sound much, but it’s significant according to the experts.
Scientists say that the lighter rock formed between 30 and 35 million years ago when hot molten material rose from deep inside Earth, spread beneath the crust and then cooled into a solid layer.
Those ancient volcanic leftovers are apparently still doing their job today.
According to the researchers, the buoyancy created by the buried slab perfectly matches the height of the Bermuda Rise, a giant underwater plateau surrounding the island.
The sea floor there sits around 1,300 to 3,300 feet higher than nearby sections of Atlantic crust of a similar age.
The Bermuda Rise has long confused geologists because there are no active volcanic hotspots underneath it today.
5 weird theories about The Bermuda Triangle
Atlantis tech – Some people believe that the lost city of Atlantis lies beneath the Bermuda Triangle, creating strange energy fields that interfere with ships and aircraft.
Alien activity – Other folk think that UFOs hidden beneath the Atlantic are responsible for disappearances in the region.
Magnetic weirdness – One theory claims unusual magnetic fields around Bermuda can confuse compasses and navigation equipment.
Methane gas eruptions – Don’t laugh. This theory suggests giant bursts of methane rising from the sea floor could suddenly sink ships by changing the density of the surrounding water. What a way to die, eh?
Time warps and dimensional portals – A few staunch believers claim that The Bermuda Triangle contains distortions in space and time that pull ships or aircraft into other dimensions. As yet, no one’s managed to come back and confirm it.
What’s even stranger is that the region also contains a slight gravitational anomaly caused by the lighter material hidden below the surface.
Because the buried rock is less dense, gravity in the area is fractionally weaker than it otherwise should be.
The ocean surface above the rise even forms a subtle bulge known as a ‘geoid anomaly’. Which sounds a little like the sort of thing a Bond villain would threaten the world with, but is actually completely natural, apparently. We’ll have to take the geologists’ word for that.
The area’s also been long linked to unusually strong magnetic signals caused by iron and titanium-rich volcanic rocks left behind from Bermuda’s ancient geological past.
Scientists say these magnetic oddities can affect compass readings slightly when ships or aircraft pass overhead. Although they’re believed to be harmless.
Researcher William Frazer said this in a statement about it: ‘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.
‘This suggests that there are other convective processes within Earth’s mantle that have yet to be well understood.’
Sadly for conspiracy theorists, this still doesn’t explain the Bermuda Triangle stuff. Or the appeal of Bermuda shorts.
Our advice? Don’t hold your breath on either.