Scientists say that the Pacific Ocean, the oldest in the world, is shrinking by about one centimeter a year. They claim that in just 200 to 300 million years, North America will collide with Asia, giving us the new supercontinent of “Amasia.”
Researchers have long had theories about what is known as the supercontinent cycle. Over billions of years, the Earth’s continents have collided with each other every 600 million years and then drifted apart again, giving rise to supercontinents such as Columbia, Rodinia, and Pangaea. Now scientists at Curtin University in Australia say that our next cycle of supercontinents will occur due to the “closing” of the Pacific Ocean. They published their work at the end of last month in the magazine National Science Review.
“By simulating how the Earth’s tectonic plates are expected to evolve using a supercomputer, we were able to show that in less than 300 million years it is likely that it will be the Pacific Ocean that will close, allowing the formation of Amasia, which discredits some previous scientific theories,” Chuan Huang, lead author, said in a press release.
The Pacific Ocean is believed to be the remnant of the Panthalassa superocean, which began to form 700 million years ago when the former supercontinent began to break up. Since then it has been shrinking, the study authors say.
One of the most discussed theories in supercontinent research is the creation of these masses through introversion or extroversion. During introversion, the youngest oceans, such as the Atlantic or the Indian Ocean, close. Extroversion supposes the closing of the Pacific Ocean, older.
Since the Pacific Ocean is receding about a centimeter a year, pushing North America westward, the world’s oldest ocean is the one that will lead us to a supercontinent, unlike other prevailing theories that the Atlantic or Indian Oceans will determine the next supercontinent, say the authors.
Their computer model uses the weakening of the force of Earth’s oceanic lithosphere (the stiff upper layer due to Earth’s cooling) as a key differentiator in the movement of the continents, increasing the likelihood that extroversion will lead to Amasia.
“Amasia could only have an extroversion mount through the closure of the Pacific Ocean due to the weakening of the oceanic lithosphere over time,” the authors say in the study. “This predicts that the next Amasia supercontinent could only be assembled through the closure of the Pacific Ocean.”
And as North America moves toward Asia, so does Australia, at about 5 centimeters a year.
Zheng-Xiang Li, a co-author of the paper, says the shift to another supercontinent will have profound implications for the Earth’s ecosystem and environment.
“Earth as we know it will be drastically different when Amasia forms,” he says in the statement. “Sea levels are expected to be lower, and the vast interior of the supercontinent will be very arid with high daily temperature ranges.” The Earth today is made up of seven continents with very different ecosystems and human cultures, so it would be fascinating to think about what the world might look like in 200 or 300 million years.”
#Introducing #Amasia #Earths #Supercontinent