Canberra Geologist Helps Advance Global Understanding Of Climate Change

Fairfax - Finbar O'Mallon

To find answers to one of the biggest issues facing the planet, University of Canberra geologist Duanne White travelled to one of its smallest, most inhospitable and isolated corners.
Associate professor White braved freezing temperatures and blizzards on the remote and tiny island of South Georgia in the South Atlantic ocean, collecting data on climate change.
He and his colleagues launched their final report in London on Friday, which showed ice sheets surrounding the island south-east of South America had shrunk faster than previously believed.

University of Canberra associate professor and geologist Duanne White at work on South Georgia in March 2013. Photo: Supplied

Mr White said ice sheets around South Georgia had shrunk to a tenth of its original size since the last ice age, likely as a result of our planet's warming climate.
He said it would help future projections on the change to ice sheets across the planet, helping model sea level rises as a result of climate change.
"It gives us some basic information about how sensitive marine based ice sheets are to ocean warming, and a much better idea for where the thresholds are for other sheets including the Antarctics," Mr White said.
Mr White said his two-week stint on South Georgia was like living in a zoo, with a huge population of fur seals, penguins and other polar and sub-polar animal life.
"I'd often be woken up at four in the morning as a baby seal would come out of the ocean and cry for its mum," Mr White said.
"It's quite the privilege being able to go to some quite remote places and to look at things that are interesting and important to the world and just plain amazing to see."

Icebergs west of South Georgia; Mr White said the report showed South Georgia's ice sheets were a tenth of their original size. Photo: Lidia Slucki

Mr White would take 'cosmogenic exposure dating samples', testing chunks of rock for isotopes created by cosmic radiation.
Seeing the amount of isotopes, like aluminium or beryllium, in the rock showed scientists how long ago the rock was covered by ice.

Mr White would be often woken up in the early hours of the morning by young seals, like this one, on South Georgia Island. 

"Basically as the ice sheet goes past the piece of bedrock it exposes that rock to cosmic rays and starts the clock," Mr White said.
"It really did rewrite our understanding of how the ice sheets on South Georgia have changed."
"The previous theory was they are more or less the same they are today."

Links

• Studying tiny island’s ice age legacy
• Sea ice spread around Antarctica hit a record low
• Extensive ice cap once covered sub-Antarctic island of South Georgia
• An ancient ice sheet pushed life to the brink at South Georgia 20,000 years ago
• Canberra geologist heads to Antarctica for fourth time to help map changes in ice sheet