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A long time ago, all continents were crammed together in a large mass of land called Pangea. The Pangea broke apart about 200 million years ago, its pieces moved on the tectonic plates, but not permanently. The continents will come together again in the deep future. And a new study, unveiled today during an online poster session at the American Geophysical Union meeting, suggests that the future settlement of this supercontinent could have a dramatic impact on Earth’s habitability and climate stability. The findings also have implications for the search for life on other planets.
The study, which has been submitted for publication, is the first to model the climate on a supercontinent in the deep future.
Scientists aren’t exactly sure what the next supercontinent will look like or where it will be. One possibility is that, in 200 million years, all continents except Antarctica may unite around the north pole, forming the supercontinent “Amasia”. Another possibility is that “Aurica” could form from all continents joining around the equator in about 250 million years.
In the new study, the researchers used a 3D global climate model to simulate how these two land mass agreements would affect the global climate system. The research was led by Michael Way, a physicist at NASA’s Goddard Institute for Space Studies, an affiliate of Columbia University’s Earth Institute.
The team found that by changing the atmospheric and oceanic circulation, Amasia and Aurica would have profoundly different effects on the climate. The planet could end up being 3 degrees Celsius warmer if the continents all converge around the equator in the Aurica scenario.
In the Amasia scenario, with the earth massed around both poles, the lack of earth in the middle disrupts the ocean conveyor belt that currently carries heat from the equator to the poles. As a result, the poles would be colder and ice covered all year round. And all that ice would reflect heat back into space.
With Amasia, “there is a lot more snowfall,” Way explained. “You get ice sheets and get this very effective ice albedo feedback, which tends to lower the planet’s temperature.”
In addition to the cooler temperatures, Way suggested that sea level would likely be lower in the Amasia scenario, with more water bound in the polar caps, and that snow conditions could mean there wouldn’t be much land available for crops in. growth.
Aurica, on the other hand, would probably be a little prettier, she said. The concentrated earth closest to the equator would absorb the strongest sunlight there, and there would be no polar caps to reflect heat from the Earth’s atmosphere – hence the highest global temperature.
Though Way compares Aurica’s coasts to Brazil’s paradisiacal beaches, “the hinterland would probably be pretty dry,” he warned. Whether or not much of the land is arable will depend on the distribution of the lakes and the types of precipitation patterns it experiences – details that the current paper does not elaborate on, but which could be studied in the future.
Simulations showed temperatures were right for liquid water to exist on about 60 percent of the earth of Amasia, compared to 99.8 percent in Aurica, a finding that could inform the search for life on other planets. One of the main factors astronomers look for when exploring potentially habitable worlds is whether or not liquid water could survive on the planet’s surface. When modeling these other worlds, they tend to simulate planets that are completely covered with oceans or whose terrain resembles that of modern Earth. The new study, however, shows that it is important to consider the disposition of the earth’s mass while estimating whether temperatures drop in the “habitable” zone between freezing and boiling.
While it may take 10 or more years before scientists can ascertain the actual distribution of land and sea on planets in other star systems, the researchers hope that having a larger library of land and sea arrangements for climate modeling could prove useful for estimating the potential habitability of neighboring worlds.
Hannah Davies and Joao Duarte of the University of Lisbon and Mattias Green of Bangor University in Wales were co-authors of this research.
Source of the story:
Materials provided by Earth Institute at Columbia University. Original written by Sarah Fecht. Note: The content can be changed by style and length.
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