Intan Rakhmayanti Dewi, CNBC Indonesia
Tech
Friday, 03/11/2023 08:40 WIB
Foto: LightRocket via Getty Images/Wolfgang Kaehler
Jakarta, CNBC Indonesia – The secret of another world that has existed beneath the East Antarctic Ice Sheet (EAIS) for 14 million years has been revealed through a study of new satellite data and radar imaging.
According to the researchers, the preservation of this ancient landscape attests to the fact that the EAIS has remained relatively unchanged for thousands of years, but this stability is threatened by an unprecedented rise in global temperatures.
The authors of this study used satellite data to identify undulations on the surface of the ice sheet that provide clues to the nature of the terrain beneath. Using radio-echo sounding techniques, they were then able to image the ice-covered landscape over an area of 32,000 square kilometers.
“The world beneath the East Antarctic Ice Sheet has not been studied much, even compared to the surface of Mars,” explained study author Professor Stewart Jamieson, quoted by IFL Science, Thursday (2/11/2023). “This is a problem because the landscape controls the flow of ice in Antarctica, and controls how that ice responds to past, current and future climate change,” he added.
The researchers identified three blocks of plateau created by rivers and separated by deep U-shaped valleys. It is likely that the waterways that shaped the landscape flowed during and after the breakup of the Gondwana supercontinent, before the first glaciers appeared and helped erode the valleys to a depth of about 800 meters.
“What we found was an ancient land surface that had not been eroded by the ice sheet and looked like it had been formed by rivers before the ice appeared,” explains Jamieson.
“This tells us that there hasn’t been much change in this area, which suggests that although parts of the ice sheet may have shrunk during warm times in the past, conditions at this location likely have not changed much,” he added.
This discovery helps researchers understand how ice sheets may respond to future and ongoing warming.
In their paper, the study authors explain that the landscape has been covered in ice for at least 14 million years. During this period, the warmest temperatures occurred about three million years ago in the mid-Piacenzian warm period. But the most reliable ice sheet models show that the EAIS does not retreat into these riverine landscapes.
In fact, it is possible that this ancient landscape was formed as early as 34 million years ago, when the EAIS first appeared after the Eocene-Oligocene transition (EOT) from warm to glacial conditions.
However, it is unclear whether the ice sheet ever retreated far enough during this period to expose and alter the three river valleys, located approximately 350 kilometers from the edge of the EAIS.
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