The world may have a new supercontinent within 200 million to 300 million years as the Pacific Ocean shrinks and closes.
Researchers at Curtin University in Australia and Peking University in China used a supercomputer to model the evolution of Earth's tectonic plates(地质构造板块) and the formation of a future supercontinent. Their findings were published in the journal National science Review.
"Over the past two billion years, Earth's continents have collided(相撞) together to form a supercontinent every 600 million years，known as the supercontinent cycle. This means that current continents are due to come together again in a couple of hundred million years time," said lead author Dr. Chuan Huang, a research fellow in Curtin's Earth Dynamics Research Group and the School of Earth and Planetary Sciences. ;
The team's simulation showed that due to the fact that Earth has been cooling for billions of years since its formation, the thickness and strength of the tectonic plates beneath the oceans have reduced over time. As a result, the formation of a new supercontinent is more likely to happen by the closing up of the Pacific Ocean. Reducing by a few centimeters per year, the Pacific Ocean's current reach of 10,000 kilometers will close up in less than 300 million years.
"The resulting new supercontinent has already been named Amasia because some believe that the Pacific Ocean will close when America collides with Asia. Australia is also expected to play a role in this important Earth event, first colliding with Asia and then connecting America and Asia once the Pacific Ocean closes," Huang said.
Changes in the distribution of continents and oceans will cause changes in climates, "particularly when ocean currents are stopped by continental collision, or new ocean currents are formed when continents break apart," said study coauthor Zheng-Xiang Li, distinguished professor in Curtin's School of Earth and Planetary Sciences. "Earth, as we know, will be completely different when Amasia forms. The sea level is expected to be lower, and the vast interior of the supercontinent will be very dry with high daily temperature ranges. "
Researchers expect more earthquakes as the continental plates collide. Surrounded by a new super ocean, the newly formed supercontinent will also have decreased biodiversity.
Scientists are still trying to understand Earth's supercontinent cycle, which is driven by heat and gravity. The research team wants to establish how Earth's tectonic plates started and when the first continents formed, as well as what kicked off the supercontinent cycle. "We are only starting to look at the entire Earth system, from its core to its atmosphere, as a closely linked system that evolved together," Li said.
