Jakarta – A new study reveals beneath East Antarctica’s undulating ice sheet lies an ancient landscape carved by rivers that provides a perfect picture of the region before glaciers covered it.
Launch detikInetalthough most of the land buried beneath the ice sheet has been eroded over millennia by the movement of ice masses, satellite data shows that the region adjacent to the Aurora and Schmidt subglacial basins remained largely intact up to 34 million years.
“We can see that there is something like a landscape under the ice,” said study co-author Stewart Jamieson, a geography professor at Durham University in England, quoted by Live Science.
“At some time in the past, there was a river flowing over it, which automatically means that it happened before the ice sheet grew,” he said.
Jamieson and his colleagues used existing data to map mounds and troughs on the surface of the ice that reflect elevation changes in the landscape beneath.
This small gradient reveals a small topographic island buried two kilometers below the surface and three land blocks separated by a U-shaped valley.
According to Jamieson, these blocks most likely form a continuous land mass. But when the ancient supercontinent Gondwana, which included Antarctica, broke apart in the Cretaceous period (145 million to 66 million years ago), tectonic forces may have torn the continent apart.
“As part of the drift away from the continents, this may expand our landscape and break it up into three blocks,” Jamieson said.
As the climate cooled after the Cretaceous, layers of ice may have formed over each block and formed valleys as the ice melted and water dripped from the peaks.
“The rivers may have flowed towards the coast, several hundred kilometers away, as the coast began to open up,” Jamieson said.
This article has appeared on detikInet, read in full here.
(mso/mso)
2023-11-02 13:00:19
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