A gigantic blob is slowly creeping towards New York City – and there’s nothing we can do to stop it.
Well, kind of. Researchers from the University of Southampton have discovered a mass of molten rock underneath the Eastern US.
The slime, known as the Northern Appalachian Anomaly, stretches 2249 miles wide and is oozing southwest at 12 miles per million years.
But don’t worry about being stuck behind it and being late to work – it sits 124 miles underground, according to the study in the journal Geology.
It’s considered a thermal anomaly because it’s far hotter than where it sits in the asthenosphere, a semi-molten layer of Earth.
Study lead and geoscientist Tom Gernon told Metro that the thermal lump has long puzzled scientists, as it doesn’t quite fit into our understanding of how contents formed.
Earth used to be a supercontinent called Pangaea. But our planet is a massive puzzle and its pieces, tectonic plates, are always moving around on a layer of molten rock.
Gernon said: ‘Imagine pulling a toffee bar apart, the toffee thins. That’s exactly what happens to continents when they’re stretched apart.’
About 180million years ago, Pangaea broke apart and North America drifted from Africa. Experts have long believed that the blob was leftover magma from this geological shift.
Yet the study, which included the Helmholtz Center for Geosciences in Germany, said the blob is a lot ‘younger’ than that.
‘We proposed it formed when Greenland and Canada separated. So, admittedly not too much younger, it’s 90million years old,’ Gernon said.
To map the molten sludge’s route, scientists used seismic tomography, which is essentially an MRI for tectonic plates.
The blobs form because of something called ‘mantle wave’ theory. The idea, Gernon said, is that hot rock sitting just outside the Earth’s core rises to fill the cracks in the crust caused by rifts.
This hot goo peels off the weakest layer of tectonic plates, ‘like the blobs of a hot lava lamp’, and lifts the crust from below.
‘Think of a hot air balloon, you’re happily bopping along and you drop the weight, you rise up. This anomaly is cutting the weight – the weakened layer of the crust – so the whole plate becomes lighter and lifts,’ Gernon said.
The seismic lava lamp could explain why the Appalachian Mountains are still standing tall despite years of erosion and why volcanic activity in the region causes diamonds to reach the surface.
As the blob drifts away from the Appalachians, the mountain range will slowly begin to sag without the thermal lift.
This syrup isn’t anything for New Yorkers to be concerned about – its centre won’t pass through the Big Apple for the next 15trillion years.
Nor will it bring about the Apocalypse when it does so. ‘It’s not going to be a big, crazy, super volcanic eruptions, nothing like that at all,’ he said.
credit: METRO GRAPHICS / Getty
‘It’s quite quiet, subtle things that happen over very long periods. Someone told me it’s the millionth of a snail’s pace – it’s not something people need to be worried about.’
While the study was focused on the Northern Appalachian Anomaly, the team also looked at a hot zone beneath North Central Greenland, which is influencing the region’s miles-thick ice sheets.
‘Something that happened 90million years ago can still have an impact on us today,’ Gernon added.
‘It’s an interesting thought experiment, to go and re-examine these ancient things that we didn’t really understand.
‘Maybe, in the light of this new idea, we can realise what interesting effects they’re having on the surface.’
Get in touch with our news team by emailing us at webnews@metro.co.uk.
For more stories like this, check our news page.
