After Paggaia, Rodinia and Nuna comes a fourth supercontinent
A vast supercontinent will form hundreds of millions of years from now. Supercontinents are giant land masses made up of many continents that could reappear on Earth 200 million years from now. Where they will form can drastically affect the climate of our planet.
Scientists recently modeled this future view of the Earth with a supercontinent and presented their findings on December 8, at the annual meeting of the American Geophysical Association (AGU), which took place online this year.
The researchers looked at two scenarios. In the first, about 200 million years into the future, almost all continents have moved to the Northern Hemisphere, with Antarctica being left alone in the Southern Hemisphere. In the second scenario, about 250 million years in the future, a supercontinent has formed around Ecuador and extends to the northern and southern hemispheres.
In both scenarios, the researchers calculated the impact on the global climate based on the topography of the supercontinent. They were surprised to find that when the continents were joined to the north and the ground was mountainous, global temperatures were significantly lower than in the other models. Such an effect could mean a period of deep cooling, lasting at least 100 million years.
New models of life on Earth show a big, chilly supercontinent emerging in 200 million years. Will tropical biodiversity …
Posted by LiveScience on Monday, December 14th, 2020
For the past 3 billion years or so, the planet has experienced many periods where continents formed vast supercontinents that then disintegrated, according to study lead author Michael Way, a scientist at NASA’s Goddard Space Research Institute in New York.
The most recent supercontinent was Pangaea, which existed about 300 million to 200 million years ago and included present-day Africa, Europe, North America, and South America. Before Paggaia was marked Rodinia (900 million to 700 million years), and before that, Nuna, which was formed 1.6 billion years ago and disintegrated 1.4 billion years ago.
Two years ago, another team of scientists modeled the supercontinent of the distant future. According to the results, in 250 million years in the future, the supercontinent “Aurica” will merge with continents around the equator, while “Amasia” will be close to the North Pole. For the new study, Way and his team took the Aurica and Amasia land masses and different topographies and entered the data into a model called ROCKE-3D.
Scientists have used various parameters for calculations, based on how the Earth changes over time. For example, 250 million years from now, the Earth will rotate a little slower than it does today, something the model took into account, Way explained.
“The rate of rotation of the Earth slows down over time. “If you travel 250 million years into the future, the length of the day will have increased by about 30 minutes, so the model calculated that,” Way said. “Solar luminosity will increase slightly in 250 million years, because the sun gradually becomes brighter over time.”
The most unexpected result in both models was that global temperatures were lower by about 4 degrees Celsius in the mountainous Amasia continent in the Northern Hemisphere. This is mainly due to the intense feedback of ice-albedo (whiteness), ie the reflectivity of the Earth – the more ice there is, the more reflective the Earth is. “Snow and ice permanently covered the northern continent during the summer and winter months, so the temperature is lower than in the other scenarios,” Way said.
By comparison, in the model where Amasia is less mountainous, lakes and inland seas could be formed. Atmospheric heat shifted north of the equator, melting snow and ice so that the earth would not freeze permanently.
Today, ocean currents carry heat to the far north, traveling around Greenland and across the Bering Strait. But when a supercontinent forms and these boulevards close, “then you can not transfer this warm ocean heat from the lower latitudes to the north,” says Way.
What can this mean for life on Earth? Along with the tropical lowlands, incredible biodiversity is disappearing. However, could new species emerge that would adapt to survive in extremely cold environments, as they did in previous ice ages?