Atlantic Ocean Could ‘Quickly’ Start to Shut

The huge stretch of ocean between the Americas and Europe could also be about to shut quickly—on a geological timescale.

Simply earlier than the continents start to float again collectively, an “Atlantic ring of fireplace” is anticipated to type, with the realm of tectonic exercise transferring from the Mediterranean into the Atlantic, in response to a brand new paper within the journal Geology.

This is because of start taking place in about 20 million years—simply across the nook geologically, however an unfathomably lengthy time period on a human scale.

Picture of the tectonic plates making up the Atlantic ocean. The Atlantic might begin to shut in round 20 million years.

Elliot Lim, CIRES & NOAA/NCEI

Tectonic plates are continually transferring, simply extremely slowly. Typically, oceans are born as plates transfer aside, and shut once more as plates transfer again collectively over a whole bunch of tens of millions of years, in a course of known as the Wilson Cycle. That is what drove the megacontinent of Pangaea to interrupt up 180 million years in the past, forming the Atlantic, and squishing the traditional ocean Tethys into what’s now the Mediterranean.

For the Atlantic to shut, new subduction zones must type. These are locations the place one plate is pressured beneath the opposite into the Earth’s mantle, occurring attributable to variations in density between the 2 plates, sometimes with an oceanic plate being subducted beneath a continental plate or one other oceanic plate.

Subduction zones are characterised by intense geological exercise, together with earthquakes, volcanic eruptions and the formation of deep oceanic trenches.

These zones are arduous to type, nevertheless, as plates are very robust and a subduction zone would require a plate to interrupt and bend. Nonetheless, subduction zones that exist already can migrate in a course of often known as subduction invasion.

In response to the paper, which used computational fashions to foretell future plate tectonics, the subduction zone within the Mediterranean beneath the Gibraltar Strait is anticipated to maneuver additional into the Atlantic in about 20 million years, forming an Atlantic ring of fireplace just like the one surrounding the Pacific.

gibraltar subduction zone map
Maps from the paper exhibiting the evolution of the Gibraltar subduction zone from 30 million years in the past to 50 million years into the long run. This subduction invasion might drive the closing of the Atlantic ocean.

João C. Duarte / Duarte et al., 2024

“Subduction invasion is inherently a three-dimensional course of that requires superior modeling instruments and supercomputers that weren’t out there just a few years in the past. We will now simulate the formation of the Gibraltar Arc with nice element and likewise the way it might evolve within the deep future,” paper co-author João Duarte, a researcher on the College of Lisbon’s Instituto Dom Luiz, stated in a press release.

The researchers describe how the Gibraltar subduction zone has slowed down over the previous few tens of millions of years, with few scientists contemplating it nonetheless energetic. After the zone enters the Atlantic, nevertheless, it’s anticipated to get way more energetic, driving the closing of the Atlantic Ocean over a number of extra tens of millions of years.

“There are two different subduction zones on the opposite facet of the Atlantic—the Lesser Antilles, within the Caribbean, and the Scotia Arc, close to Antarctica. Nonetheless, these subduction zones invaded the Atlantic a number of million years in the past. Learning Gibraltar is a useful alternative as a result of it permits observing the method in its early levels when it’s simply taking place,” Duarte stated.

The researchers concluded that invasive subduction could also be a standard method that oceans just like the Atlantic begin to shut, and subsequently could also be a significant factor in how our planet has geologically developed.

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