Antarctic glaciers could have existed for 60 million years, says research

Antarctic glaciers could have existed for 60 million years, says researchPrevious research suggested glaciers only formed around 34 million years ago.  Glaciers could have been present in Antarctica's mountain regions for at least 60 million years – almost double the time interval previously predicted by experts – according to new research.

Currently, Antarctica – the Earth's southern-most continent – is almost completely covered in ice, with around 90% being glacial.

Previous studies have suggested that glaciers first appeared on the continent immediately before the formation of the first ice sheet, which is said to have been around 34 million years ago.

However, new research published in Nature Communications, led by scientists from Manchester Metropolitan University, suggest glaciers could have been present in the most mountainous regions of the continent significantly earlier.

Scientists say it help them understand how the area will be impacted by climate change in the future.

"It would have been a dramatically different climate in the region at this time, with subtropical forests and dinosaurs still roaming around – but what we found was evidence that in the very highest mountains, glaciers were present."

Using satellite images, researchers analysed tens of thousands of glacial landforms known as glacial cirques (or corries) – large glacially eroded bowl-shaped hollows.

They then reconstructed the climate conditions needed for glaciers to form.

In doing so, they found it was possible that glaciers were present in the highest mountain regions of the continent – the Transantarctic Mountains, a 3500 km mountain chain that extends across the continent – at least 60 million years ago.

Dr Iestyn Barr, Reader in Physical Geography at Manchester Metropolitan University, said: "Antarctica reached its current polar location roughly 80 million years ago, but it's often been presumed that substantial glaciers didn't form until roughly 34 million years ago, coinciding with dramatic global cooling.

"But what we wanted to explore is whether glaciers could have existed before this time, when the climate in the continent was significantly warmer.

"It would have been a dramatically different climate in the region at this time, with subtropical forests and dinosaurs still roaming around – but what we found was evidence that in the very highest mountains, glaciers were present – a lot like what we see today in places like the South American Andes."Dr Barr explains how this discovery can help us not only understand more about Antarctica's glacial past, but also helps us to look to the continent's future – in particular how the landscape will change as a result of global warming.

He added: "Our findings are interesting as they help us to understand Antarctica's long-term future, as we would expect it to go back to a similar landscape at some point.

"In the distinct future, the climate of Antarctica is likely be substantially warmer than now, and this is being sped up due to recent climate change.

"We now believe there will still be glaciers – as we know they can exist in more tropical climates than previously thought – but not as we know them to be now. They will be much smaller versions." 

https://www.mmu.ac.uk/news-and-events/news/story/15675/