Ancient topography of rivers emerges beneath Antarctica’s icy surface | Travel

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Antarctica has not always been an empty expanse of ice and snow. The southernmost continent of our planet was once inhabited by rivers and forests bursting with life.

An illustration shows the unveiling of a landscape similar in size to Belgium in Wilkes Land, East Antarctica after the removal of the thick ice sheet covering it, as discovered by scientists using ice penetrating radar and satellite observations. (Stewart Jamieson, Durham University/Handout via REUTERS)
An illustration shows the unveiling of a landscape similar in size to Belgium in Wilkes Land, East Antarctica after the removal of the thick ice sheet covering it, as discovered by scientists using ice penetrating radar and satellite observations. (Stewart Jamieson, Durham University/Handout via REUTERS)

A glimpse into Antarctica’s ancient terrain is now attainable through satellite observations and ice-penetrating radar. Researchers announced on Tuesday the discovery of a vast prehistoric landscape buried deep beneath the continent’s icy sheet, adorned with valleys and ridges that were sculpted by rivers before being engulfed by the ice age millions of years ago.

This ancient landscape can be found in the Wilkes Land region of East Antarctica, bordering the Indian Ocean, covering an area roughly equivalent to Belgium or the US state of Maryland. The investigators estimate that this landscape dates back at least 14 million years, possibly even further to 34 million years, when Antarctica went into its frozen enthrallment.

“This landscape is akin to a snapshot of the past,” commented Stewart Jamieson, one of the study’s leaders and a glaciology professor at Durham University in England. “While it is challenging to imagine what this lost world would have looked like before the ice took over, we do know that it was certainly warmer at that time. Depending on the era we are referring to, the climate could have spanned from the current climate of Patagonia to something more tropical. In fact, paleontologists have discovered ancient palm tree pollen in Antarctica, not far from our research site,” Jamieson added.

According to Jamieson, this formerly verdant environment would have likely teemed with animal life, although the available fossil record cannot confirm which creatures inhabited it.

The ice layer above this ancient terrain measures approximately 1.4-1.9 miles (2.2 km to 3 km) in thickness, as determined by Neil Ross, a polar science and environmental geophysics professor at Newcastle University in England and co-leader of the study.

Unlocking the mysteries of the subglacial land has proven to be more challenging than exploring the surface of Mars, according to the researchers. One proposed method of uncovering its secrets involves drilling into the ice to extract core samples from the underlying sediments. Such samples could provide evidence of the ancient flora and fauna, similar to what has been done in Greenland with samples dating back 2 million years.

The study employed satellite observations of the ice surface, which in certain areas mirrored the contours of the buried landscape, as well as ice-penetrating radar data collected from an aircraft flying over the site.

Previous studies have also revealed ancient landscapes beneath Antarctica’s ice, including mountains and highlands, but the discovery in this new study represents the first of its kind.

“Over geological time, this landscape has been shaped by a combination of different processes influenced by rivers, tectonic activity, and glaciation,” said Ross.

Prior to approximately 34 million years ago, Antarctica’s landscape and vegetation likely resembled the cold temperate rainforests of Tasmania, New Zealand, and Patagonia in South America, Ross added.

At one point, Antarctica was part of the Gondwana supercontinent, which also included present-day Africa, South America, Australia, the Indian subcontinent, and the Arabian Peninsula. Eventually, Antarctica separated and became isolated through the process of plate tectonics.

Jamieson hypothesized that when Antarctica experienced a warmer climate, rivers flowed across the newly exposed landscape towards a continental coastline that formed following the breakup of other land masses. As the climate cooled, small glaciers developed on hills along the riverbanks, causing the valleys to deepen through glacial erosion.

“Subsequently, the climate experienced a more significant cooling event, resulting in the growth of an ice sheet that covered the entire continent and overwhelmed any existing glaciers. During this ice expansion, the conditions between the base of the ice sheet and the landscape became extremely cold, halting further erosion. Consequently, the landscape was preserved for an estimated 34 million years,” Jamieson elaborated.

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This story has been published from a wire agency feed without modifications to the text. Only the headline has been changed.

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