The Atlantic Ocean Will Be Sucked Into the Earth

Scientists believe the Atlantic Ocean could be swallowed by a subduction zone (where tectonic plates collide) in a narrow gap between Spain and Morocco.

A new study predicts this dramatic change, though thankfully, it won't happen for a very long time – roughly 20 million years.

A subduction zone, an area where tectonic plates collide and one dives beneath the other. This process, responsible for mountain formation and even ocean closure, is currently happening beneath the Strait of Gibraltar, the narrow waterway separating Spain and Morocco.

Scientists believe this subduction zone will gradually expand westward, intruding into the Atlantic Ocean. This "invasion" will eventually trigger the Atlantic to shrink, marking the beginning of its closure.

The study, published in the journal Geology, used computer models to simulate the future of the Atlantic Ocean. The models showed that as the African tectonic plate continues to move north, it will eventually collide with the Eurasian plate. This collision will create a subduction zone under the Strait of Gibraltar.

The Gibraltar subduction zone

Oceans: Born, Grow, Die

Unlike our limited lifespans, oceans are constantly in flux. They form, expand, and eventually close over hundreds of millions of years, a process known as the Wilson Cycle. The Atlantic itself arose from the breakup of the supercontinent Pangaea around 180 million years ago, and the Mediterranean Sea is just a remnant of a much larger ocean that once existed between Africa and Eurasia.

For an ocean to start shrinking, new subduction zones need to form. But creating these zones is a challenge because tectonic plates are incredibly strong and resist bending and breaking.

Subduction Invasion: A New Twist

This study proposes a novel solution to this "paradox": subduction zone migration. Imagine a subduction zone like a hungry consumer. It can "steal" itself from a shrinking ocean (like the Mediterranean) and invade a healthy one (like the Atlantic). This process is called subduction invasion.

The research, based on advanced computer models, predicts that the sluggish subduction zone under the Strait of Gibraltar will eventually become more active and invade the Atlantic. This will trigger the formation of an "Atlantic Ring of Fire," mirroring the one already present in the Pacific Ocean.

20 Million Years of Peace, Then the Fury?

While the Atlantic's closure won't happen for millennia, the study sheds light on the ongoing activity beneath the Strait of Gibraltar. Some scientists believed this subduction zone was dormant, but the research suggests it's just in a slow phase – a phase that will last for another 20 million years.

After this extended period of relative calm, the invasion will commence, accelerating the closure of the Atlantic and initiating the recycling of the ocean floor on its eastern side.

Seismic Risks Remain

This research also highlights the ongoing seismic threat posed by the Gibraltar subduction zone. Subduction zones are notorious for generating powerful earthquakes, including the devastating 1755 Great Lisbon Earthquake. The study's findings emphasize the importance of preparedness for future seismic events in the region.

The broader implication of this research is that subduction invasion might be a common phenomenon in Atlantic-type oceans, playing a crucial role in shaping our planet's geological history.