Nov. 18 - Scientists working in eastern Antarctica believe they have found the world's oldest ice sheet which, they say, could provide information on future climate change. The researchers estimate the ice sheet is 1.5 million years old, almost twice the age of the previous oldest sample. Tara Cleary reports.
PLEASE NOTE: THIS EDIT CONTAINS MATERIAL THAT WAS ORIGINALLY 4:3 It's taken fifteen years of research but scientists say they've found Antarctica's oldest ice-sheet. At 1.5 million years of age, it's a landmark discovery according to researcher Tony Press. SOUNDBITE: TONY PRESS, ANTARCTIC CLIMATE RESEARCHER, SAYING (English): "It's the Holy Grail of ice core science really, to find a climate record that goes back to the time when the climate fluctuated more frequently than it does at the moment." The sheet is about three kilometres thick. Dr. Tas van Ommen says it took aerial technology to find it. SOUNDBITE: DR. TAS VAN OMMEN, AUSTRALIAN ANTARCTIC DIVISION, SAYING (English): "You send pulses of radio waves into the ice, it bounces off the bedrock underneath and reflects back and you can work out then how thick the ice is." Van Ommen says carbon dioxide contained in air bubbles trapped in the ice will reveal how atmospheric CO2 levels have fluctuated over the past 1.5 million years, and how they might affect climate chage in the future. SOUNDBITE: DR. TAS VAN OMMEN, AUSTRALIAN ANTARCTIC DIVISION, SAYING (English): "It pulsed the ice ages more rapidly when the CO2 was higher. Now we're going into an era where we're raising CO2 levels." Despite Antacrtica's extreme conditions, the team hopes to start drilling within five years to try to extract a three kilometre long ice core sample. By unlocking the continent's ancient climate secrets they say they hope to inform the decisions of future generations.