US, WASHINGTON (ORDO NEWS) — When Roald Amundsen was the first in the history of mankind to reach the South Pole on December 14, 1911, it was unlikely that a brave researcher thought about how this area looked 90 million years ago.
But now, scientists have found that in the prehistoric past, Antarctica was a temperate and somewhat swampy rainforest with an average temperature of about 12 ° C. In the summer, scientists say, the temperature warmed up to 19 ° C.
Their findings, published in the journal Nature, are based on soil samples that they believe are from the middle of the Cretaceous, that is, from 115 to 80 million years ago.
According to a team of scientists from Great Britain and Germany, an analysis of the preserved roots and other plant debris in the soil shows that the world was warmer at that time than is commonly believed.
Tina van de Flierdt, spokeswoman for the Department of Earth and Engineering Sciences at Imperial College London, said: “The fact that this forest has survived 90 million years is an exceptional, but even more amazing, world that it’s conceals in itself. If so mild tropical rainforests grew so close to the South Pole, “despite the months of darkness,” it means the climate was warmer than we thought before.”
Scientists analyzed the ice core extracted from the seabed near the Pine Island and Twits glaciers in western Antarctica.
They found well-preserved forest soil, including plant pollen, spores, a dense root network, and the remains of flowering plants.
Ulrich Salzmann, a paleoecologist at the University of Northumbria and another study co-author, said: “Numerous plant debris suggests that 93-83 million years ago the coast of western Antarctica was a swampy landscape with temperate rainforests similar to those now grow, say, on the southern island of New Zealand.”
To better imagine the climate of that era, the researchers tried to simulate what conditions would suit the plants found. It turned out that summer temperatures are around 19 degrees, and the water in rivers and swamps warms up to 20 degrees.
According to the researchers, the amount and intensity of precipitation in western Antarctica was the same as in today’s Wales.
In addition, from the data obtained it follows that the level of carbon dioxide in the atmosphere in the middle of the Cretaceous period – the generally recognized age of dinosaurs – was also higher than previously thought.
According to Gerrit Lohmann, a climate modeling specialist at the Alfred Wegener Institute at the Polar and Marine Research Center. Helmholtz and another co-author of the study: “Before our study, it was generally accepted that the global concentration of carbon dioxide in the Cretaceous was about a thousand parts per million.”
“But according to our model experiments, it turns out that concentrations of 1,120 to 1,680 ppm are required to achieve such average temperatures in Antakrtid.”
Researchers have yet to find out why the climate subsequently cooled enough to form extensive ice sheets typical of Antarctica.
“Our climate modeling does not yet provide a satisfactory answer,” concluded Prof. Lohmann.
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