Amasia, the supercontinent that will form on Earth

Amasia, Earth’s next supercontinent, will likely form when the Pacific Ocean closes, in about 200 to 300 million years. If we could travel to the past, millions of years ago, we would not recognize our planet: the Earth is a geologically active world in which the crust is in continuous movement, creating and destroying itself without stopping.

However, the times in which the changes occur are invaluable to our human eyes. Although it is hard for us to believe, all the continents that we see now, in the past they joined and broke several times, sank and emerged again. They completely changed. And the process is not over yet.

Geologists point out that the movements of the Earth’s continents are cyclical and that each 500 to 700 million years a is created supercontinent. The last time was about 300 million years ago, when pangea it was formed to break (and give rise to the current terrestrial configuration) 100 million years later, in the middle of the age of the dinosaurs.

That is why scientists suspect that it will happen again in about 200 or 300 years. Now, a new study conducted by researchers at Curtin University (Australia) and published in ‘National Science Review‘ delves into what this Earth of the future will be like and they predict that the key will be in the closure of the old Pacific Ocean.

How the ground moves under our feet

The continents move due to the circulation that occurs in the layer under the seven major tectonic plates. One plate is ‘forced’ under another in a process called subduction, which in turn breaks the crust on the opposite side of the plate, allowing new molten rock to bubble to the surface to fill the gap.

This process causes the ocean floor to be constantly created and destroyed. However, the continents are made of less dense rock than the heavy ocean floor, so they rise above the waters and escape subduction. This is how the continents maintain their shape for hundreds of millions of years as they slowly slide across the planet.

However, they inevitably collide and sometimes come together to form a supercontinent. Pangea was the last, but before that, around 1.1 billion years ago, another called rodinia, which broke 250 million years later. Before that there was another one and almost certainly many more before it, but since the formation of a supercontinent tends to destroy the evidence of the previous one, we cannot be sure how many times it has happened since the creation of our planet.

Two future scenarios including Amasia

Right now we are in the middle of a cycle: the Pacific is closing as ocean deposits sink into North Pacific subduction zones. For its part, the Atlantic is growing as new ocean floor is created. As the Americas pull away from Europe, Australia moves north and into Southeast Asia. All this in an almost negligible ‘dance’ of continents of 15 millimeters per year.

Geologists look two scenarios: one in which a subduction zone opens in the Atlantic and the ocean floor retracts, causing Europe and America to collide; and a second in which the Atlantic continues to expand, and America and Asia collide, forming a supercontinent already baptized as Amasia. This last hypothesis is the one pointed to by the data of the aforementioned study.

supercontinent and superocean

In their models, the team found that because the Earth has been cooling for billions of years, the thickness and strength of the plates under the oceans have reduced over time, making it difficult to ‘assemble’. of the next supercontinent from the closure of the ‘young’ oceans, such as the Atlantic or the Indian (that is, from the first scenario mentioned).

Instead, models suggest that the Pacific Ocean will most likely close, allowing Amasia to form, “debunking some earlier scientific theories”points Chuanhuang, of the Curtin Earth Dynamics Research Group and the School of Earth and Planetary Sciences and lead author of the study.

The Pacific Ocean is what remains of the superocean Panthalassa, which began to form 700 million years ago when Pangea began to break apart. It is currently the oldest ocean we have on Earth, and it is gradually shrinking by a few centimeters per year. Its current dimension of about 10,000 kilometers is expected to take between 200 and 300 million years to close.

“Earth as we know it will be drastically different when Amasia forms. Sea levels are expected to be lower, and the vast interior of the supercontinent will be very arid with high daily temperature ranges.”explains Zheng-Xiang Li, also from the Curtin School of Earth and Planetary Sciences. “The Earth currently consists of seven continents with very different ecosystems and human cultures, so it is fascinating to think about what the world will look like in 200 to 300 million years”.

Font: PATRICIA BIOSCA / ABC

Reference article: https://www.abc.es/ciencia/amasia-proximo-supercontinente-formara-tierra-20221003181323-nt.html