Pioneering Research at Antarctica’s Totten Glacier Reveals the Melting of the South Pole from Below
by Carolyn Sotka
Totten Glacier (Photo: Esmee van Wijk)
The Totten Glacier is the largest part of the Eastern Antarctic ice sheet and historically thought to be less vulnerable to climate change and more stable than other areas of the South Pole. Over the last 15 years though, satellite images have shown that the glacier was thinning, but the reason was unclear. The uncertainty was due to the inaccessibility of the glacier for sampling. According to Dr Steve Rintoul, from the Antarctic Climate and Ecosystems CRC, up to now, Totten has been one of the world’s largest and least understood glacial systems. No oceanographic measurements had been made within 50 kilometers of its ice.
An international team of scientists, led by Rintoul and equipped with new technologies and robust icebreaker vessels were finally able to reach the glacier and collect samples for the first time during a 7-week research voyage earlier this year. What they found was that Totten Glacier was actually melting from below due to intrusion of warm ocean water. As Totten and other floating glaciers around the edge of Antarctica melt, more glacial ice can flow into the ocean, raising sea level.
The Aurora Australis alongside the Totten Glacier (Photo: Paul Brown)
The Australian Antarctic Division estimates that Totten alone holds enough water to raise sea level by six meters. The Antarctic ice sheet is the largest single mass of ice on earth and includes the South Pole. Approximately 70% of the world’s freshwater is held in the ice sheet. Were it to melt, sea levels could rise 58 meters. This study can help address one of the biggest questions concerning future sea level rise; how will warming of the ocean affect the Antarctic ice sheet.
A mooring retrieved from the sea bed near the Totten Glacier (Photo: Steve Rintoul)
A key part of the voyage was the recovery of US and Australian instruments moored on the seabed for up to two years at six different locations adjacent to the Totten glacier. The Australian instruments are part of the national Integrated Marine Observing System (IMOS). The instruments were deployed by the US icebreaker Nathaniel B. Palmer and recovered by the Australian icebreaker Aurora Australis as part of an ongoing international collaboration.
To learn more about the study visit Australia’s Antarctic Program Web site.