Madrid, 4 (Europe Press)
“At that time, many parts of the world experienced summers that were warmer than today,” said Irina Rogozina, concluding evidence obtained in an investigation in which she participated as associate professor in the Department of Geography at NTNU (Norwegian University of Science and Technology).
“Although this type of response of the East Antarctic ice sheet to heat during the Holocene was not entirely expected, it is still difficult and troubling to think that the East Antarctic ice sheet could change so rapidly,” he said.
It is difficult to find a simple and easy explanation for this behavior, or to pinpoint the exact moment when the melt occurred, especially since conditions in this part of the world are sometimes quite inhospitable.
But Rozguchina and her collaborators have found a way to unravel this mystery. They examined several nunatak rocks in Queen Maud Land for exposure to cosmic radiation.
“Nunatak are mountains sticking out of the ice. We visited Nunatak and took samples,” says Ola Fredin, professor in the Department of Earth and Petroleum Sciences and co-author of the study published in Communications Earth & Environment.
Researchers are examining different isotopes, or variants, of elements such as chlorine, aluminum, beryllium and neon in the nunatak rocks. With the help of cosmic isotopes, they can work out how high the ice has been during geological time in Queen Maud Land. Friedan likens it to using a dipstick to measure the engine oil level in your car.
In this way, researchers can tell something about how long the rocks have been exposed to cosmic radiation. Then they can also say something about how long it has been since the rocks were under a protective layer of ice and thus did not absorb any cosmic radiation.
To do this, they use data from different regions and run a variety of computer simulations.
Researchers also think they are on their way to finding out why the East Antarctic Ice Sheet strip shrank so much immediately after the last ice age ended.
“We think the ice sheet is becoming less stable due to rising sea levels in the region and warmer water rising from the ocean depths in the polar regions, breaking through ice edges and melting from below. This leads to the breakup of large icebergs and accelerates the movement of ice from the land to the ocean, causing This in turn leads to a thinning of the interior of the ice sheet. The process is similar to when a house on a hillside loses its foundation and starts sliding downhill.”
In short, the less stable and faster-flowing parts of the East Antarctic ice sheet, called ice shelves and floating on the ocean, break up more easily, in turn causing the ice sheet to break. relatively short period. Time, in geological terms, or a few hundred to thousands of years.
